OF 


RTHOUA. 


THE  WONDER  BOOK  OF 
VOLCANOES  AND  .EARTHQUAKES 


THE 

WONDER  BOOK 

OF 

VOLCANOES  AND  EAETHQUAKES 


BY 


PROFESSOR  EDWIN  J.  HOUSTON,  Pn.D. 


NEW  YORK 

FREDERICK   A.   STOKES  COMPANY 
PUBLISHERS 


NOV  6 

Jo  . 


WITHDRAW!* 


Copyright,  1907,  by 
FREDERICK  A.  &TOKES  COMPANT 


.  All.  rigfos  reserved  ( 


Geology 


1W 

ACKNOWLEDGMENTS 

We  take  this  opportunity  of  acknowledging  the  courtesy 
of  the  following  publishers,  who  have  helped  us  in  con- 
nection with  the  illustrations  of  this  book: — 

Henry  Holt  and  Company  ("Physiography,"  by 
Rollin  D.  Salisbury). 

D.  Appleton  and  Company  (Figs.  13,  35,  39,  40,  41, 
42,  43,  44,  45  and  46,  "Volcanoes:  What  They  Are  and 
What  They  Teach,"  by  J.  W.  Judd;  Fig.  15,  "Princi- 
ples of  Geology,"  by  Sir  C.  Lyell). 

The  American  Book  Company  ("Manual  of  Geology," 
by  James  D  wight  Dana). 

G.  P.  Putnam's  Sons  ("Earthquakes  in  the  Light  of 
the  New  Seismology,"  by  C.  E.  Dutton). 

The  Clarendon  Press  ("Geology:  Chemical,  Physical, 
and  Stratigraphical,"  by  Joseph  Prestwich). 

THE  PUBLISHERS. 


CONTENTS 

CHAPTER  PAGE 

I.     THE  VOLCANIC  ERUPTION  OF  KRAKATOA  IN  1883  1 

II.     SOME  EFFECTS  OF  THE  ERUPTION  OF  KRAKATOA  12 

III.     THE  VOLCANIC  ISLAND  OF  HAWAII 26 

IV.    THE  VOLCANIC  ISLAND  OF  ICELAND 46 

V.     VESUVIUS 58 

VI.     OTHER  VOLCANOES  OF  THE  MEDITERRANEAN  .     .  73 
VII.     ORIZABA,    POPOCATEPETL,    IXTACCIHUATL,    AND 

OTHER  VOLCANOES  OF  MEXICO 85 

VIII.     COSEGUINA  AND  OTHER  VOLCANOES  OF  CENTRAL 

AMERICA 91 

IX.     THE  VOLCANIC  MOUNTAINS  OF  SOUTH  AMERICA  .  97 

X.     VOLCANOES  OF  THE  UNITED  STATES 105 

XI.     THE  CATASTROPHE  OF  MARTINIQUE  AND  THE  VOL- 
CANIC ISLANDS  OF  THE  LESSER  ANTILLES  .     .     .  117 
XII.     SOME  OTHER  NOTED  VOLCANIC  MOUNTAINS   .     .  125 

XIII.  JORULLO,  A  YOUNG  VOLCANIC  MOUNTAIN  .     .     .  130 

XIV.  MID-OCEAN  VOLCANIC  ISLANDS 137 

XV.     SUBMARINE  VOLCANOES 141 

XVI.     DISTRIBUTION  OF  THE  EARTH'S  VOLCANOES  .     .  148 

XVII.     VOLCANOES  OF  THE  GEOLOGICAL  PAST  ....  153 

XVIII.     LAPLACE'S  NEBULAR  HYPOTHESIS 157 

XIX.     THE  EARTH'S  HEATED  INTERIOR,  THE  CAUSE  OF 

VOLCANOES 165 

XX.     SOME  FORMS  OF  LAVA 178 

XXI.     MUD  VOLCANOES  AND  HOT  SPRINGS 193 

XXII.     THE  VOLCANOES  OF  THE  MOON 207 

XXIII.  EARTHQUAKES 219 

XXIV.  SOME  OF  THE  PHENOMENA  OF  EARTHQUAKES  .     .  231 
XXV.     THE  EARTHQUAKE  OF  CALABRIA  IN  1783  .     .     .  245 

XXVI.     THE  GREAT  LISBON  EARTHQUAKE  OF  1755  .     .     .  252 

XXVII.     THE  EARTHQUAKE  OF  CUTCH,  INDIA,  IN  1819  .     .  257 
XXVIII.     THE  SAN  FRANCISCO  EARTHQUAKE  OF  APRIL  18, 

1906        262 

[Vii] 


CONTENTS 


CHAPTER  PAGE 

XXIX.     SOME  OTHER  NOTABLE  EARTHQUAKES   ....  269 
XXX.     SODOM  AND  GOMORRAH  AND  THE  CITIES  OF  THE 

PLAIN 281 

.  XXXI.     INSTRUMENTS  FOR  RECORDING  AND  MEASURING 

EARTHQUAKE  SHOCKS 290 

XXXII.     SEAQUAKES 296 

XXXIII.  THE  DISTRIBUTION  OF  EARTHQUAKES  ....  303 

XXXIV.  THE  CAUSES  OF  EARTHQUAKES 308 

XXXV.     EARTHQUAKES  OF  THE  GEOLOGICAL  PAST — CATA- 
CLYSMS     319 

XXXVI.     THE  KIMBERLY  DIAMOND    FIELDS  AND  THEIR 

VOLCANIC  ORIGIN 326 

XXXVII.     THE  FABLED  CONTINENT  OF  ATLANTIS  ....  335 

XXXVIII.     PLATO'S  ACCOUNT  OF  ATLANTIS 344 

XXXIX.    NATURE'S  WARNING  OF  COMING  EARTHQUAKES  .  364 


FULL  PAGE  ILLUSTRATIONS 


PAGE 

MT.  VESUVIUS  IN  ERUPTION FRONTISPIECE 

STONES  AND  LAVA  THROWN  UPWARDS — ERUPTION  OF  Mo- 

KUAWEOWEO,  HAWAII,  JULY  4-21, 1899 fac.  36 

COTOPAXI  102 

THE  LAVA  FLOW  OF  THE  CRATER  OF  KILAUEA,  HAWAIIAN 

ISLANDS 184 

A  SAN  FRANCISCO  PAVEMENT  TORN  BY  THE  EARTHQUAKE  266 


ILLUSTRATIONS  IN  TEXT 

FIG.  PAGE 

1.  THE  SUNDA  ISLANDS 3 

2.  KRAKATOA  BEFORE  THE  ERUPTION 4 

3.  KRAKATOA  AFTER  THE  ERUPTION 4 

4.  VOLCANIC  DUST  AS  IT  APPEARS  UNDER  THE  MICROSCOPE  19 

5.  THE  HAWAIIAN  ISLANDS 27 

6.  HAWAII 29 

7.  PANORAMA  OF  MOKUAWEOWEO 35 

8.  VIEW  OP  THE  CRATER  OF  KILAUEA  FROM  THE  VOLCANO 

HOUSE       35 

9.  CRATER  OF  KILAUEA 40 

10.  SECTIONS  OF  KILAUEA  AT  DIFFERENT  PERIODS  ....  42 

11.  ICELAND       47 

12.  THE  MEDITERRANEAN 59 

13.  THE  VOLCANIC  DISTRICT  AROUND  VESUVIUS 60 

14.  MT.  ETNA 77 

15.  STROMBOLI,  VIEWED  FROM  THE  NORTHWEST,  APRIL,  1874  79 

16.  MEXICO  AND  CENTRAL  AMERICA 86 

17.  SOUTH  AMERICA 98 

18.  THE  UNITED  STATES 106 

19.  PANORAMA  FROM  THE  MESA  AT  THE  EDGE  OF  MT.  TAYLOR  110 

20.  VOLCANIC  NECKS,  EDGE  OF  MESA  AT  MT.  TAYLOR  .     .     .  Ill 

21.  THE  LESSER  ANTILLES 118 

22.  GRAHAM'S  ISLAND — A  RECENT  VOLCANIC  ISLAND  .     .     .  143 

23.  ALEUTIAN  ISLANDS 146 

24.  MAP  OF  THE  WORLD,  SHOWING  LOCATION  OF  ACTIVE  AND 

RECENTLY  EXTINCT  VOLCANOES 150 

25.  VOLCANIC  VESICLES 183 

26.  THREAD-LACE  SCORIAE  FROM  KILAUEA 185 

27.  THREAD-LACE  SCORIA  FROM  KILAUEA 185 

28.  FROST-LIKE  LAVA  CRYSTALS 187 

29.  FROST-LIKE  LAVA  CRYSTALS 187 

30.  BASALTIC  COLUMNS,  ISLE  OF  CYCLOPS,  ITALY     ....  188 

[xi] 


xii  ILLUSTRATIONS  IN  TEXT 


FIG.  PAGE 

31.     COLUMNAR  AND  NON-COLUMNAR  BASALT 189 

32, 33.     DRIBLET  CONES 190 

34.  LAVA  STALACTITES 191 

35.  CRATER  OF  THE  GREAT  GEYSER  OF  ICELAND 202 

36.  GIANT  GEYSER 203 

37.  BEE  HIVE 203 

38.  BEE  HIVE  GEYSER  OF  ICELAND 205 

39.  HEAVY  STONE  OBELISKS  TWISTED  BY  CALABRIAN  EARTH- 

QUAKE OF  1783 229 

40.  CIRCULAR  HOLLOW  FORMED  BY  CALABRIAN  EARTHQUAKE  239 

41.  SECTION  OF  CIRCULAR  HOLLOW  FORMED  BY  CALABRIAN 

EARTHQUAKE 239 

42.  MAP  OF  THE  CALABRIAN  EARTHQUAKE  OF  1783   ....  246 

43.  FISSURES  CAUSED  BY  THE  CALABRIAN  EARTHQUAKE  .     .  249 

44.  MAP  SHOWING  DISTRICT  VISITED  BY  THE  EARTHQUAKE  OF 

CUTCH  OF  1819 258 

45.  SINDREE  BEFORE  THE  EARTHQUAKE  OF  1819 259 

46.  SINDREE  AFTER  THE  EARTHQUAKE  OF  1819 260 

47.  MAP  OF  WESTERN  COAST  OF  CALIFORNIA  SHOWING  POSI- 

TION OF  SAN  FRANCISCO 263 

48.  NEW   ZEALAND 274 

49.  MAP  SHOWING  REGION  AFFECTED  BY  THE  CHARLESTON 

EARTHQUAKE  OF  1886 277 

50.  SYRIA 282 

51.  COMPLEX  RECORD  OF  SEISMOGRAPH 293 

52.  LONG  DISTANCE  SEISMOGRAM •   .  293 

53.  VICENTINI  VERTICAL  PENDULUM 294 

54.  VICENTINI  PENDULUM  AND  RECORDER .  295 

55.  DAVISON'S  EARTHQUAKE  MAP  OF  JAPAN 306 


THE  WONDER  BOOK  OF 
VOLCANOES  AND  EARTHQUAKES 


THE    WONDER    BOOK    OF    VOLCANOES 
AND  EARTHQUAKES 

CHAPTER  I 

THE    VOLCANIC    ERUPTION     OF     KRAKATOA    IN    1883 

Krakatoa  is  a  little  island  in  the  Straits  of  Sunda,  about 
thirty  miles  west  of  the  island  of  Java,  and  nearly  the 
same  distance  east  of  the  island  of  Sumatra.  It  is  unin- 
habited and  very  small,  measuring  about  five  miles  in 
length  and  less  than  three  miles  in  width.  Its  total  area 
is  only  thirteen  square  miles.  This  little  piece  of  land 
made  itself  famous  by  what  took  place  on  it  during  the 
month  of  August,  1883. 

Krakatoa  is  one  of  the  many  islands  that  form  the  large 
island  chain  known  as  the  Sunda  Islands.  The  most  im- 
portant islands  of  this  chain  are  Sumatra,  Java,  Sum- 
bawa,  Flores,  and  Ceram.  Between  Sumatra  and  Java, 
the  largest  two  of  these  islands,  there  is  a  channel  called 
the  Straits  of  Sunda  that  connects  the  waters  of  the 
Indian  Ocean  with  those  of  the  Pacific  Ocean.  The 
Straits  of  Sunda  is  an  important  piece  of  water  that  forms 
one  of  the  great  highways  to  the  East.  Shipping  is,  there- 
fore, always  to  be  found  in  its  waters. 

As  can  be  seen  by  the  map,  Krakatoa  is  not  far  from 
the  Equator,  being  situated  in  lat.  6°  7'  S.  and  long. 
105°  26'  E.  from  Greenwich.  Since  there  are  about  sixty- 

A  [1] 


2  VOLCANOES  AND  EARTHQUAKES 

nine  miles  in  every  degree  of  latitude,  Krakatoa  is  about 
420  miles  south  of  the  Equator,  and  is  about  twenty-five 
miles  from  Java.  Java  is  part  of  the  Dutch  East  Indies, 
which  includes  Java,  Celebes,  the  Spice  Islands,  and  parts 
of  Borneo  and  Sumatra.  Batavia,  the  principal  seaport  of 
Java,  near  the  northwest  coast,  is  a  great  shipping  centre, 
visited  by  vessels  from  nearly  all  parts  of  the  world.  It 
has,  however,  no  harbor,  but  is  approached  from  the 
ocean  by  means  of  a  canal  two  miles  in  length,  the  sides 
of  which  are  provided  with  massive  brick  walls.  Besides 
Batavia,  which  is  situated  about  one  hundred  English 
miles  east  of  Krakatoa,  there  are  many  smaller  towns  or 
villages,  the  most  important  of  which  is  Anjer,  a  thriving 
seaport  town,  where  sailing  vessels  obtain  their  supplies 
of  food  and  fresh  water.  Before  the  eruption  of  Krakatoa, 
Anjer  was  provided  with  a  strong,  stone  lighthouse. 

Java  is  especially  noted  for  its  production  of  coffee,  in 
which  it  is  second  only  to  Brazil.  Its  area  is  about  the 
same  as  that  of  the  State  of  New  York.  Java  is  one  of 
the  most  densely  populated  parts  of  the  world,  contain- 
ing nearly  four  times  as  many  people  as  the  whole  State 
of  New  York. 

These  facts  about  the  situation  and  surroundings  of 
Krakatoa  are  necessary  to  an  understanding  of  the  won- 
derful thing  that  happened  on  it  during  the  month  of 
August,  1883.  In  that  month  Krakatoa  suffered  a  most 
tremendous  explosive  volcanic  eruption,  for  it  is  a  volcano. 

A  volcano  is  a  mountain  or  hill,  generally  conical  in 
shape,  having  at  the  top  a  nearly  central  opening,  called 
a  crater,  from  which  at  times  melted  rock  and  lava,  vapor 
and  gases  escape.  The  lava  either  flows  down  the  side 
of  the  mountain  in  a  liquid  condition,  or  is  thrown  up- 
wards into  the  air.  If  the  distance  the  lava  is  thrown 
upwards  is  sufficiently  great  the  melted  matter  solidifies 


ERUPTION  OF  KRAKATOA 


VOLCANOES  AND  EARTHQUAKES 


Forsaken  (, 


Lang  I. 


before  it  falls  to  the  earth.     In  such  cases  the  largest 
fragments  form  what   are    called   volcanic   cinders,    the 

smaller  pieces,  vol- 
canic ashes,  and  the 
extremely  small  par- 
ticles, volcanic  dust. 
If,  however,  the  lava 
is  thrown  to  a  com- 
paratively small 
height,  it  is  still 
melted  when  it  falls, 
and  is  then  known 
as  volcanic  drops  or 
driblets. 

It  is  not  surpris- 
ing that  Krakatoa 
is  a  volcanic  island, 

since  it  lies  in  one  of  the  most  active  belts  of  volcanic 
islands  in  the  world,  and  near  the  coasts  of  the  most  ac- 
tive of  these  islands; 
i.e.,  Java.  This 
belt,  as  shown  in 
the  map,  includes, 
besides  the  Sunda 
Island  chain,  parts 
of  Gilolo,  Celebes, 
Mindanao  and  the 
Philippine  Islands. 
These  islands  lie  be- 
tween Asia  on  the 
northwest  and  Aus- 


FIG.  2.   KKAKATOA  BEFORE  THE 
ERUPTION 


Lang  I. 


Krakntoa  I. 


tralia  on  the  south- 
east. 

There  is  no  other  part  of  the  world  with,  perhaps,  the 


FIG.  3.   KRAKATOA  AFTER  THE 
ERUPTION 


ERUPTION  OF  KRAKATOA  5 

single  exception  of  Japan,  where  so  many  active  volcanoes 
are  crowded  in  so  small  a  space.  The  island  of  Java, 
small  as  it  is,  has  nearly  fifty  volcanoes,  of  which  at  least 
twenty-eight  are  active.  They  are  situated  in  a  lofty 
range  running  from  east  to  west,  some  of  the  peaks  of 
which  are  more  than  10,000  feet  above  the  level  of  the 
sea.  Volcanic  eruptions  are  so  frequent  that  the  island 
is  seldom  free  from  them. 

As  will  be  seen  from  the  map  shown  in  Fig.  2,  Kraka- 
toa  consists  of  three  groups  of  volcanic  mountains,  the 
southern  group  giving  the  name  of  Krakatoa  to  the  island. 
Strictly  speaking,  this  mountain  was  called  Rakata,  but  as 
it  is  now  generally  known  as  Krakatoa,  it  would  be  un- 
wise to  attempt  to  call  it  by  any  other  name.  The  cen- 
tral mountain  or  group  of  mountains  is  known  as  Danan, 
and  consists  largely  of  part  of  an  old  crater.  The  group 
of  mountains  which  lies  near  the  northern  end  of  the 
island  was  known  as  Perboawatan.  From  the  centre  of 
this  latter  group  of  mountains  are  several  old  lava 
streams  consisting  of  a  variety  of  lava  resembling  a 
dark-colored  glass,  known  to  mineralogists  as  obsidian, 
or  volcanic  glass. 

Although  Krakatoa  was  always  a  volcano,  yet  between 
the  years  1680  and  1883,  it  was  in  the  condition  of  a  sleep- 
ing or  extinct  volcano.  There  had  been  a  severe  explosive 
eruption  in  the  year  1680,  that  caused  great  loss  of  life 
and  property,  but  ever  since  that  time  all  activity  had 
ceased  and  it  seemed  that  the  volcano  would  never  again 
burst  out.  In  other  words,  it  was  generally  regarded  as 
a  trustworthy,  sedate,  quiet,  inoffensive  and  perfectly 
safe  volcano,  that  had  become  extinct. 

The  long  continued  quiet  of  Krakatoa  was  broken  on 
the  20th  of  May,  1883,  when  the  inhabitants  of  Batavia 
on  the  island  of  Java  were  terrified  by  noises  like  the  firing 


6  VOLCANOES  AND  EARTHQUAKES 

of  great  guns,  that  were  first  heard  between  ten  and 
eleven  o'clock  in  the  morning.  These  noises  were  accom- 
panied by  the  shaking  of  the  ground  and  buildings.  The 
sleeping  volcano  of  Krakatoa  was  evidently  growing  rest- 
less, but  no  great  damage  was  done  and  soon  all  was  again 
quiet.  The  disturbances  were  merely  the  forerunner  of 
the  terrible  eruption  soon  to  follow,  and  confidence  was 
soon  restored.  But  suddenly,  on  Sunday,  August  26th, 
1883,  almost  without  any  further  warnings,  Krakatoa 
burst  into  terrible  activity  and  began  an  explosive  erup- 
tion that  has  never  been  equalled  in  severity  in  the 
memory  of  man. 

That  memorable  Sunday  of  August  26th,  1883,  came 
during  a  season  of  the  year  known  as  the  dry  monsoon,  a 
name  given  the  season  of  the  periodical  winds  from  the 
Indian  Ocean.  Batavia,  and  the  surrounding  country, 
greatly  needed  rain,  for  in  this  part  of  the  world  it  seldom 
rains  from  April  to  October,  although  the  air  is  very  moist 
and  damp.  For  this  reason  the  beginning  of  the  wet 
season  is  always  welcomed.  When,  therefore,  the  rum- 
bling sounds  of  the  approaching  catastrophe  of  Krakatoa 
were  heard  in  Batavia,  the  people,  believing  that  the 
noises  were  due  to  peals  of  thunder,  rejoiced,  for  all 
thought  they  heralded  an  earlier  setting  in  of  the  wet 
monsoon.  But  when  the  rumbling  sounds  increased  and 
reports  were  heard  like  heavy  artillery,  it  was  clear  that 
the  sounds  were  the  beginning  of  a  volcanic  eruption, 
a  phenomenon  with  which  they  were  only  too  well  ac- 
quainted, but,  as  volcanic  eruptions  were  far  from  being 
uncommon  in  Java,  no  one  was  very  greatly  frightened. 

But  this  time  the  noises  increased  to  such  an  extent 
that  the  people  became  alarmed.  Throughout  the  night 
the  appalling  sounds  continued  and  were  accompanied  by 
shakings  of  the  earth  sufficiently  strong  to  shake  the 


ERUPTION  OF  KRAKATOA  7 

houses  violently.  Sleep  was  out  of  the  question.  Many 
of  the  people  left  their  houses  and  remained  all  night  in 
the  open  air,  fearing  the  shocks  would  bring  the  houses 
down  over  their  heads. 

The  morning  instead  of  heralding  the  dawn  of  a  beau- 
tiful tropical  day,  with  its  bright,  cheerful  sunlight, 
brought  with  it  skies  covered  with  gray  clouds  that  com- 
pletely hid  the  sun.  The  rumbling  sounds,  however,  had 
decreased,  and  the  people  were  beginning  to  congratulate 
themselves  that  the  dangers  were  over,  when  suddenly, 
the  sky  grew  darker,  and  there  began  a  shower  of  ashes 
that  soon  covered  the  streets  and  houses  of  the  city. 
About  seven  o'clock  on  the  morning  of  August  27th,  a 
most  tremendous  crash  was  heard.  The  sky  rapidly  be- 
came so  dark  that  it  was  soon  necessary  to  light  the  lamps 
in  the  houses  of  Batavia,  and  some  of  the  neighboring 
towns  in  the  western  part  of  Java.  In  addition  to  this  the 
air  was  filled  with  vapor,  while  every  now  and  then  earth- 
quake shocks  were  again  felt.  These  shocks  were  accom- 
panied by  terrific  noises  like  those  produced  by  the  explo- 
sion of  heavy  artillery.  The  noises  rapidly  increased  in 
number  and  intensity  until  they  produced  a  nearly  con- 
tinuous roar,  the  nature  of  which  it  is  almost  impossible  to 
describe  since  it  is  probable  that  such  sounds  had  never 
been  heard  before  by  man.  It  is  a  curious  fact,  which,  I 
believe,  has  never  heen  satisfactorily  explained,  that  in 
most  cases  the  people  in  the  immediate  neighborhood  of 
the  volcano,  as,  for  example,  those  on  board  vessels  in 
the  Straits  of  Sunda,  did  not  hear  the  terrific  noises  at 
all.  Possibly  they  were  too  loud  and  simply  gave  a 
single  inward  impetus  to  the  drum  of  the  ear  and  then 
held  it  in  position. 

Probably  some  of  my  readers  may  remember  that  witty 
description  given  by  Dr.  Oliver  Wendell  Holmes  of  an 


8  VOLCANOES  AND  EARTHQUAKE^ 

alleged  effort  made  by  all  the  people  of  the  world  to  find 
out  whether  or  not  there  is  a  man  in  the  moon.  This 
wonderful  plan  was  as  follows: 

Careful  calculations  were  made  to  ascertain  when  it 
would  be  the  same  time  over  all  the  earth  so  that  all  the 
people  of  the  earth  could  simultaneously  shout  at  the  top 
of  their  voices.  In  this  way  it  was  hoped  that  the  man 
in  the  moon,  if  there  were  such  a  person,  would  notice  the 
noise. 

The  story  goes  on  to  tell  how  when  the  time  approached 
for  the  great  experiment,  and  all  were  ready  to  shout  as 
loud  as  they  could,  that  each  person  reasoning  to  himself 
or  herself,  that  amid  so  great  a  noise  no  one  could  notice 
whether  his  or  her  voice  was  omitted,  determined  to  re- 
main silent,  so  as  to  be  able  to  hear  the  noise  and  the  better 
to  observe  what  the  man  in  the  moon  would  do  when,  the 
sound  reached  him.  The  result  was  that  every  person  on 
the  earth  remained  silent,  and  simply  listened,  so  that  the 
earth  was  never  so  quiet  before. 

Had  Oliver  Wendell  Holmes,  or  any  other  person  con- 
ceiving the  witty  idea,  lived  during  the  time  of  the  great 
explosive  eruption  of  Krakatoa,  on  that  memorable 
August  27th,  1883,  he  might  have  taken  the  opportunity 
of  observing  the  man  in  the  moon,  had  he  not  been  fright- 
ened by  what  was  occurring,  for  certainly  never  before 
were  such  tremendous  or  terrifying  sounds  produced,  for 
these  sounds,  as  we  shall  see  shortly,  were  actually  heard 
for  distances  of  more  than  3,000  miles  from  the  volcano. 

There  were  two  different  kinds  of  waves  produced  in 
the  air  by  the  tremendous  forces  at  work  in  the  eruption 
of  Krakatoa;  namely,  atmospheric  waves  and  sound 
waves. 

The  atmospheric  waves  showed  their  presence  in  the 
air  by  means  of  changes  produced  in  the  atmospheric 


ERUPTION  OF  KRAKATOA  9 

pressure.  Now,  while  these  changes  cannot  readily  be 
felt  by  man,  yet  their  presence  can  be  easily  shown  by  the 
use  of  instruments  called  barometers. 

There  are  in  different  parts  of  the  world,  buildings 
called  meteorological  observatories,  that  are  provided, 
among  other  instruments,  with  recording  barometers. 
These  instruments  caught  the  great  atmospheric  waves 
that  were  produced  by  the  eruption  of  Krakatoa.  In  this 
manner,  the  astounding  fact  was  learned  that  the  waves 
starting  from  the  volcano  travelled  no  less  than  seven 
times  around  the  world.  When  we  say  astounding,  it 
must  not  be  understood  that  the  formation  of  such  waves 
was  at  all  contrary  to  the  known  laws  of  physics.  On 
the  contrary,  provided  the  force  of  the  eruption  was  suffi- 
ciently great,  such  waves  must  have  been  produced  in  the 
great  aerial  ocean.  The  astonishing,  or  wonderful  thing, 
was  that  the  force  setting  up  these  waves  was  so  great 
that  it  caused  them  to  move  seven  times  around  the  globe. 

The  atmospheric  waves  were  so  powerful  that  it  will 
be  worth  our  while  to  describe  them  in  detail.  Starting 
from  the  volcano  of  Krakatoa,  as  a  centre,  these  waves 
moved  outwards  in  all  directions,  becoming  gradually 
larger  and  larger  until  they  reached  a  point  halfway 
round  the  globe,  or  180°  from  Krakatoa.  The  waves  did 
not,  however,  stop  here,  but  continued  moving  onward, 
now  growing  smaller  and  smaller  until  they  reached  a 
point  in  North  America,  immediately  opposite  Krakatoa. 
Such  a  point  on  a  globe  is  called  an  antipodal  point.1  The 
waves  did  not  stop  at  this  point,  but  again  advanced 
moving  toward  Krakatoa,  growing  larger  and  larger  until 
they  again  reached  a  point  halfway  around  the  globe, 
or  180°  from  Krakatoa,  when  they  again  continued 

1  A  point  on  the  other  side  of  the  earth  directly  opposite  a  given 
point. 


10  VOLCANOES  AND  EARTHQUAKES 

moving  but  now  continually  growing  smaller  and  smaller, 
until  they  reached  Krakatoa.  Here  they  again  began 
moving  completely  around  the  globe,  and  this  was  con- 
tinued for  as  many  as  seven  times.  It  must  not  be  sup- 
posed that  the  waves  ceased  on  the  seventh  time  around. 
On  the  contrary,  they,  probably,  kept  on  moving  for  many 
additional  times,  but  they  were  then  so  feeble  that  even 
the  sensitive  recording  barometers  were  unable  to  detect 
their  presence. 

There  was  another  kind  of  waves  in  the  atmosphere  that 
did  not  require  barometers  for  their  detection.  These 
were  the  sound  waves,  and  can  readily  be  detected  by  the 
human  ear. 

Now,  in  the  case  of  the  great  eruption  of  Krakatoa,  the 
intensity  of  the  sounds  was  so  great  that  the  sounds  could 
be  heard  distinctly  at  distances  of  several  thousand  miles 
from  Krakatoa. 

The  sound  waves  so  closely  resembled  the  explosion  of 
artillery  that  at  Acheen,  a  port  on  the  northern  coast  of 
Sumatra,  1,073  miles  from  Krakatoa,  the  authorities, 
believing  that  an  attack  was  being  made  on  the  port, 
placed  all  their  troops  under  arms  to  repel  the  invaders. 
The  sounds  were  also  distinctly  heard  at  Bangkok,  in 
Siam,  a  distance  of  1,413  miles  from  the  volcano.  They 
were  also  heard  at  the  Chagos  Islands,  a  group  of  islands 
situated  in  the  Indian  Ocean  about  2,267  miles  from 
Krakatoa. 

Two  steamers  at  Singapore,  522  miles  distant,  were 
despatched  to  find  the  vessel  that  was  believed  to  be  firing 
guns  as  distress  signals. 

The  sounds  were  distinctly  heard  in  parts  of  South 
Australia,  2,100  miles  distant,  and  in  Western  Australia, 
at  1,700  miles  distance. 

But  it  will  be  unnecessary  to  give  any  further  details 


ERUPTION  OF  KRAKATOA  11 

of  the  great  distances  at  which  these  sounds  were  actually 
heard.  It  will  suffice  to  say  that  they  were  heard  as  far 
off  as  about  3,000  miles. 

It  is  difficult  to  picture  to  one's  self  such  great  distances. 
Assuming  the  greatest  distances  to  be  in  the  neighborhood 
of  3,000  miles,  it  would  be  as  if  a  sound  produced,  say,  in 
Boston,  New  York,  or  Philadelphia,  was  so  loud  that  it 
could  be  heard  in  Amsterdam,  London,  or  Paris. 

Some  idea  of  the  intensity  of  these  sounds  can  be  had 
from  the  fact  that  in  Batavia,  when,  in  accordance  with 
usage,  a  gun  was  fired  from  one  of  the  forts  at  eight  o'clock 
in  the  morning,  two  hours  before  the  greatest  intensity  of 
the  sounds  had  been  reached,  the  sound  of  the  gun  could 
scarcely  be  heard  above  the  continuous  roar. 

While,  of  course,  the  principal  reason  the  sound  waves 
were  carried  so  far  was  the  great  force  causing  the  erup- 
tion, yet  these  distances  were  increased  by  the  fact  that 
the  explosion  occurred  in  a  region  almost  entirely  sur- 
rounded by  great  bodies  of  water.  The  waves  could, 
therefore,  be  readily  carried  along  the  surface  of  the  sea. 
Had  there  been  a  high  mountain  wall,,  like  the  Andes  of 
South  America,  on  one  side  of  the  volcano  they  would 
probably  have  been  shut  off  in  this  direction  a  short  dis- 
tance from  where  they  were  produced. 


CHAPTER  II 

SOME  EFFECTS    OF   THE    ERUPTION    OF    KRAKATOA 

Besides  the  sound  waves  in  the  air,  there  were  waves  in 
the  waters  of  the  ocean.  Suddenly,  without  any  warning, 
the  people  of  Batavia  were  surprised  by  a  huge  wave  that, 
crossing  the  Straits  of  Sunda,  entered  the  ship  canal  before 
referred  to  as  connecting  the  city  with  the  ocean,  and, 
rising  above  the  brick  wall,  poured  over  the  surrounding 
country. 

Although  Batavia  was  100  English  miles  from  Krakatoa, 
yet  after  travelling  this  distance  the  wave  was  sufficiently 
strong  to  enter  the  city  and  flood  its  streets  with  water  to 
a  depth  of  several  feet.  Fortunately,  the  loss  of  life  was 
small  in  the  city  of  Batavia,  but  very  great  in  the  sur- 
rounding towns  and  villages. 

The  ocean  waves  varied  in  height  at  different  times  of 
the  eruption.  The  greatest  were  from  fifty  to  eighty 
feet  high.  Just  imagine  the  effect  of  a  wave  twice  the 
height  of  an  ordinary  house.  The  waves  caused  great 
damage  to  the  shipping  in  the  neighborhood.  In  one 
instance,  a  vessel  was  carried  one  and  a  half  miles  inland 
and  left  on  dry  land  thirty  feet  above  the  level  of  the  sea. 

The  total  loss  of  life  by  the  waves  has  been  estimated 
at  35,000  people;  besides  this,  of  course,  there  was  a  great 
amount  of  property  destroyed.  The  greatest  loss  was  in 
the  immediate  neighborhood  of  Krakatoa.  Gigantic 
waves  swept  over  the  lowlands  lying  near  the  shores  of 
Sumatra  and  Java,  where  over  areas  several  miles  in  width 
[12] 


EFFECTS  OF  ERUPTION  13 

nearly  everything  was  destroyed,  the  houses,  trees,  and 
people  being  swept  away  and  the  surface  of  the  land 
greatly  changed.  The  towns  of  Karang  and  Anjer,  as  well 
as  numerous  smaller  villages,  were  almost  completely 
destroyed. 

The  seaport  town  of  Anjer,  by  far  the  most  important 
of  the  above  towns,  was  almost  completely  swept  away. 
The  heavy  stone  lighthouse  was  so  completely  obliterated 
that  no  traces  of  its  heavy  stone  foundations  could  after- 
wards be  found.  The  Rev.  Phillip  Neale,  formerly  a 
British  chaplain  at  Batavia,  from  whose  account  of  the 
eruption  of  Krakatoa  some  of  the  above  facts  have  been 
taken,  tells  of  the  brave  action  of  the  keeper  of  the  light- 
house at  Anjer.  Besides  his  work  as  lighthouse  keeper,  to 
see  that  the  light  was  constantly  burning  during  the  night, 
he  was  charged  with  telegraphing  to  Batavia  the  names  of 
all  passing  vessels.  On  the  fateful  morning  of  the  great 
catastrophe,  observing  that  the  sun  did  not  rise,  he  kept 
the  light  of  the  lighthouse  burning,  and,  notwithstanding 
the  danger  to  which  he  was  exposed,  continued  at  his 
post  in  order  to  send  word  to  Batavia  of  the  passing  of  an 
English  steamer.  While  doing  this  the  lighthouse  was 
swept  away  and  the  brave  man  perished. 

The  following  verbal  account  of  the  destruction  of  the 
port  of  Anjer  was  given  by  a  Dutch  pilot  stationed  at 
Anjer.  This  description  is  quoted  by  the  Rev.  Mr.  Neale 
from  an  article  prepared  by  him  for  publication  in  "The 
Leisure  Hour." 

"  I  have  lived  in  Anjer  all  my  life,  and  little  thought  the 
old  town  would  have  been  destroyed  in  the  way  it  has.  I 
am  getting  on  in  years,  and  quite  expected  to  have  laid 
my  bones  in  the  little  cemetery  near  the  shore,  but  not 
even  that  has  escaped  and  some  of  the  bodies  have  actu- 
ally been  washed  out  of  their  graves  and  carried  out  to 


14  VOLCANOES  AND  EARTHQUAKES 

sea.  The  whole  town  has  been  swept  away,  and  I  have 
lost  everything  except  my  life.  The  wonder  is  that  I 
escaped  at  all.  I  can  never  be  too  thankful  for  such  a 
miraculous  escape  as  I  had. 

"The  eruption  began  on  the  Sunday  afternoon.  We 
did  not  take  much  notice  at  first,  until  the  reports  grew 
very  loud.  Then  we  noticed  that  Krakatoa  was  com- 
pletely enveloped  in  smoke.  Afterwards  came  on  the 
thick  darkness,  so  black  and  intense  that  I  could  not  see 
my  hand  before  my  eyes.  It  was  about  this  time  that  a 
message  came  from  Batavia  inquiring  as  to  explosive 
shocks,  and  the  last  telegram  sent  off  from  us  was  telling 
you  about  the  darkness  and  smoke.  Towards  night  every- 
thing became  worse.  The  reports  became  deafening, 
the  natives  cowered  down  panic-stricken,  and  a  red,  fiery 
glare  was  visible  in  the  sky  above  the  burning  mountain. 
Although  Krakatoa  was  twenty-five  miles  away,  the 
concussion  and  vibration  from  the  constantly  repeated 
shocks  were  most  terrifying.  Many  of  the  houses  shook 
so  much  that  we  feared  every  minute  would  bring  them 
down.  There  was  little  sleep  for  any  of  us  that  dreadful 
night.  Before  daybreak  on  Monday,  on  going  out  of 
doors,  I  found  the  shower  of  ashes  had  commenced,  and 
this  gradually  increased  in  force  until  at  length  large 
pieces  of  pumice  stone  kept  falling  around.  About  six 
A.  M.  I  was  walking  along  the  beach.  There  was  no  sign 
of  the  sun,  as  usual,  and  the  sky  had  a  dull,  depressing 
look.  Some  of  the  darkness  of  the  previous  day  had 
cleared  off,  but  it  was  not  very  light  even  then.  Looking 
out  to  sea  I  noticed  a  dark,  black  object  through  the  gloom, 
travelling  towards  the  shore. 

"At  first  sight  it  seemed  like  a  low  range  of  hills  rising 
out  of  the  water,  but  I  knew  there  was  nothing  of  the  kind 
in  that  part  of  the  Sunda  Strait.  A  second  glance — and 


EFFECTS  OF  ERUPTION  15 

a  very  hurried  one  it  was — convinced  me  that  it  was  a 
lofty  ridge  of  water  many  feet  high,  and  worse  still,  that 
it  would  soon  break  upon  the  coast  near  the  town.  There 
was  no  time  to  give  any  warning,  and  so  I  turned  and  ran 
for  my  life.  My  running  days  have  long  gone  by,  but  you 
may  be  sure  that  I  did  my  best.  In  a  few  minutes  I  heard 
the  water  with  a  loud  roar  break  upon  the  shore.  Every- 
thing was  engulfed.  Another  glance  around  showed  the 
houses  being  swept  away  and  the  trees  thrown  down  on 
every  side.  Breathless  and  exhausted  I  still  pressed  on. 
As  I  heard  the  rushing  waters  behind  me,  I  knew  that  it 
was  a  race  for  life.  Struggling  on,  a  few  yards  more 
brought  me  to  some  rising  ground,  and  here  the  torrent 
of  water  overtook  me.  I  gave  up  all  for  lost,  as  I  saw  with 
dismay  how  high  the  wave  still  was.  I  was  soon  taken  off 
my  feet  and  borne  inland  by  the  force  of  the  resistless 
mass.  I  remember  nothing  more  until  a  violent  blow 
aroused  me.  Some  hard,  firm  substance  seemed  within 
my  reach,  and  clutching  it,  I  found  I  had  gained  a  place 
of  safety.  The  waters  swept  past,  and  I  found  myself 
clinging  to  a  cocoanut  palm-tree.  Most  of  the  trees  near 
the  town  were  uprooted  and  thrown  down  for  miles,  but 
this  one  fortunately  had  escaped  and  myself  with  it. 

"The  huge  wave  rolled  on,  gradually  decreasing  in 
height  and  strength  until  the  mountain  slopes  at  the  back 
of  Anjer  were  reached,  and  then,  its  fury  spent,  the  water 
gradually  receded  and  flowed  back  into  the  sea.  The 
sight  of  those  receding  waters  haunts  me  still.  As  I  clung 
to  the  palm-tree,  wet  and  exhausted,  there  floated  past 
the  dead  bodies  of  many  a  friend  and  neighbor.  Only  a 
mere  handful  of  the  population  escaped.  Houses  and 
streets  were  completely  destroyed,  and  scarcely  a  trace 
remains  of  where  the  once  busy,  thriving  town  originally 
stood.  Unless  you  go  yourself  to  see  the  ruin  you  will 


16  VOLCANOES  AND  EARTHQUAKES 

never  believe  how  completely  the  place  has  been  swept 
away.  Dead  bodies,  fallen  trees,  wrecked  houses,  an 
immense  muddy  morass  and  great  pools  of  water,  are  all 
that  is  left  of  the  town  where  my  life  has  been  spent.  My 
home  and  all  my  belongings  of  course  perished — even  the 
clothes  I  am  wearing  are  borrowed — but  I  am  thankful 
enough  to  have  escaped  with  my  life  and  to  be  none  the 
worse  for  all  that  I  have  passed  through." 

As  is  common  in  cases  of  earthquake  waves  a  great 
depression  in  the  level  of  the  sea  occurred  at  places  great 
distances  from  Krakatoa.  For  example,  at  the  harbor  of 
Ceylon,  the  water  receded  so  far  that  for  about  three 
minutes  the  boats  were  left  high  and  dry,  and  then  a  huge 
wave  carried  them  with  it  as  it  rushed  over  the  land. 

Perhaps  one  of  the  best  evidences  of  the  immense  power 
of  ocean  waves  is  to  be  seen  in  the  massive  blocks  of 
white  coral  rock  that  were  washed  up  by  the  waves,  on 
parts  of  the  coast  of  Java  for  distances  of  from  two  to 
three  miles  from  the  ocean.  Many  of  these  blocks  weighed 
from  twenty  to  thirty  tons.  Indeed,  some  of  them 
reached  the  weight  of  from  forty  to  fifty  tons. 

It  is  probable  that  the  island  of  Krakatoa  and  its 
neighboring  smaller  islands  formed  portions  of  a  huge 
cone  about  eight  miles  in  diameter,  that  has  been  broken 
up  at  some  very  remote  but  unknown  time  by,  perhaps,  a 
greater  catastrophe  than  that  of  August,  1883. 

In  the  Straits  of  Sunda  the  water  was  raised  fifty  feet 
to  eighty  feet  above  the  ordinary  level,  and  produced 
tremendous  destruction  especially  on  the  coasts  of  Java 
and  Sumatra,  sweeping  away  many  villages  and  drowning 
many  thousands  of  people.  The  wave  had  a  velocity  of 
progression  of  nearly  400  miles  per  hour,  or  eight  times 
faster  than  an  ordinary  express  train. 

When  it  is  said  that  the  velocity  of  progression  of  the 


EFFECTS  OF  ERUPTION  17 

wave  was  nearly  400  miles  per  hour,  it  is  not  meant  that 
a  body  floating  on  the  ocean,  such,  for  example,  as  a  ship, 
would  have  been  carried  forward  at  this  high  velocity,  but 
would  merely  rise  and  fall  in  a  to-and-fro  swing  to  about 
the  height  of  the  wave;  that  is,  fifty  to  eighty  feet  accord- 
ing to  what  may  have  been  the  height.  As  in  the  case  of 
the  sound  waves  these  motions  of  water  covered  or  passed 
over  nearly  all  the  waters  of  the  earth.  The  waves  pro- 
gressing toward  the  west,  crossed  the  Indian  Ocean 
reaching  to  the  coast  of  Hindostan,  and  Madagascar,  and 
sweeping  around  the  southern  part  of  Africa,  finally 
reached  the  coasts  of  France  and  England,  as  well  as  the 
eastern  part  of  North  and  South  America.  Sweeping 
towards  the  east,  they  reached  the  coasts  of  Australia, 
New  Zealand,  and  crossing  the  vast  Pacific  Ocean  were 
felt  at  Alaska  and  the  western  coasts  of  North  and  South 
America. 

But  besides  the  enormous  waves  caused  by  the  eruption, 
there  were  marked  changes  in  the  level  of  the  land.  Large 
portions  of  the  coast  of  Sumatra  and  Java  were  almost 
annihilated,  much  of  the  original  surface  near  the  coast 
being  submerged,  and  places  that  were  formerly  dry  land 
are  now  covered  with  water  to  a  depth  of  from  600  to  900 
feet. 

The  enormous  amount  of  material  thrown  into  the  air 
by  the  forces  of  the  eruption  is  especially  characteristic 
of  this  phenomenon.  Such  quantities  of  pumice  stone 
and  ashes  fell  from  the  clouds  that,  sinking  in  the  water 
and  collecting  on  the  bed  of  the  channel,  they  changed 
the  depth  of  the  water,  so  as  to  render  navigation  dan- 
gerous. Indeed,  the  Sebesi  Channel,  lying  on  the  north 
of  the  island  of  Krakatoa  was  completely  blocked  by 
a  huge  bank  of  volcanic  material,  portions  of  which 
projected  above  the  water,  forming  two  smaller  islands. 

B 


18  VOLCANOES  AND  EARTHQUAKES 

These,  however,  have  since  been  washed  away  by  the 
waves. 

We  will  not  attempt  to  give  at  present  any  explanations 
as  to  the  causes  of  this  great  volcanic  eruption,  since  the 
different  theories  as  to  the  cause  of  volcanoes  will  be  better 
understood  when  other  volcanic  eruptions  have  been 
described.  It  is  sufficient  here  to  say  that  if  a  large 
quantity  of  water  should  have  suddenly  reached  a  great 
mass  of  molten  rock,  frightful  explosive  eruptions  would 
have  occurred,  and  if  the  island  was  resting  on  a  sub- 
merged crater  its  sudden  disappearance  may  be  explained. 

Another  great  wonder  connected  with  the  explosive 
eruption  of  Krakatoa  was  the  enormous  heights  to  which 
the  fine  dust  was  thrown  up  into  the  air.  It  has  been 
asserted  that  during  the  most  intense  of  these  eruptions 
the  particles  reached  elevations  of  perhaps  more  than 
twenty-five  miles  above  the  level  of  the  sea.  Carried  by 
the  winds,  the  fine  particles  remained  suspended  in  the 
air  for  many  months,  and  gave  rise  to  magnificent  sun- 
light effects,  such  as  early  dawn,  lengthened  twilights, 
lurid  skies,  and  gorgeous  sunsets  of  a  reddish  tint.  TherS 
were  also  caused  curious  haloes,  as  well  as  green  and  blue 
moons. 

The  fine  dust  particles  consisted  of  minute  crystals  of 
feldspar  and  other  minerals,  and  when  examined  under 
the  microscope  presented  the  appearance  shown  in  Fig.  4. 

These  mineral  substances  permitted  a  portion  of  the 
light  to  pass  through  them,  thus  producing  wonderful 
optical  effects  in  the  atmosphere  either  because  they  acted 
like  minute  prisms  and  so  produced  rainbow  colors,  or 
because  they  turned  the  rays  of  light  out  of  their  course 
as  to  produce  what  is  called  interference  by  color  effects 
of  a  nature  similar  to  the  colors  seen  in  mother-of-pearl, 
rainbow  coal,  or  in  the  wing  cases  of  many  beetles.  The 


EFFECTS  OF  ERUPTION 


19 


explanations  of  these  phenomena  are  too  difficult  for  a 
book  of  this  character. 

An  explosive  volcanic  eruption  is  a  very  terrifying  and 
wonderful  phenomenon.  Frightful  roaring  sounds  are 
suddenly  heard,  the  earth  shakes  for  many  miles  around, 
when  suddenly  a  vast  quantity  of  molten  rock,  and  some- 
times huge  stones,  are  thrown  out  of  the  crater  high  up 
into  the  air.  So  great  is  the  force  that  throws  these 
materials  out  of  the  opening  that  heavy  masses  of  rocks 
often  are  ejected  very  much  faster  than  the  projectiles 
from  the  largest  guns  that  are  used  in  any  of  the  navies 
of  the  world. 

As  the  molten  lava  cools 
and  falls  in  the  form  of  pro- 
digious clouds  of  ashes,  cin- 
ders and  dust,  for  many  miles 
around  the  volcano,  even  the 
light  of  the  sun  is  obscured, 
and  one  cannot  see  the  hand 
before  the  face.  Some  of  the 
materials  in  these  clouds  are 
so  light  that  they  remain  sus-  FIG.  4.  VOLCANIC  DUST  AS  IT 
pended  in  the  air  for  many  APPEARS  UNDER  THE  MICRC- 
hours,  often  indeed  for  many  SCOPE 
days,  and  sometimes  even  for  years.  The  heavier  par- 
ticles, however,  soon  begin  to  fall,  and  before  long  the 
earth's  surface  both  around  the  volcano,  and  often  at 
considerable  distances  from  it,  is  covered  with  a  thick 
layer  of  ashes. 

The  sounds  accompanying  a  volcanic  eruption  are  often 
terrifying.  Amid  shakings  and  tremblings  of  the  earth's 
crust,  known  as  earthquakes,  there  are  occasionally  heard 
noises  like  the  explosion  of  huge  guns.  Sometimes  these 
sounds  follow  one  another  so  rapidly  that  they  produce  an 


20  VOLCANOES  AND  EARTHQUAKES 

almost  continuous  roar.  Through  the  roar  of  the  explo- 
sion a  curious  crackling  noise  can  be  heard,  due  to  the 
fragments  of  stone  hurled  out  of  the  crater  striking  against 
one  another,  especially  as  the  stones  which  are  thrown 
out  of  the  crater  and  have  commenced  to  fall  back  again 
to  the  earth,  are  struck  by  others  that  are  still  rising. 

Immense  quantities  of  ashes,  stones,  vapor  and  gases 
are  thrown  upwards  for  great  distances  into  the  air,  while, 
at  the  same  time,  a  lava  stream  pours  over  the  lowest 
side  of  the  crater.  As  the  column  of  ashes  and  cinders 
reaches  its  greatest  height  in  the  air,  it  begins  to  spread 
outward  on  all  sides,  rapidly  growing  like  a  huge  dark 
mushroom.  This  soon  shuts  out  the  light  of  the  sun,  and 
from  it  showers  of  red  hot  ashes  and  cinders  fall  to  the 
earth. 

It  would  be  extremely  dangerous  to  be  on  the  side  of 
the  volcanic  mountain  during  an  explosive  eruption;  for, 
even  should  you  escape  falling  into  an  opening  in  the  side 
of  the  mountain,  you  might  be  killed  by  the  huge  stones 
that  are  constantly  falling  on  all  sides  around  the  open- 
ing, or  might  be  buried  under  the  vast  showers  of  red 
hot  ashes  that  are  poured  down  from  the  dense  clouds 
overhanging  the  mountain,  or  suffocated  by  clouds  of 
sulphur  vapor  that  rush  down  its  sides. 

When  at  a  safe  distance  the  sight  is  certainly  mag- 
nificent. There  is  no  light  from  the  sun.  All  would  be  in 
pitch  darkness  but  for  the  reddish  glare  thrown  upwards 
by  the  red  hot  lava,  by  the  glowing  showers  of  ashes  that 
are  being  rained  down  on  the  sides  of  the  mountain,  or 
by  terrific  lightning  flashes,  due  to  the  discharge  of  the 
immense  quantities  of  electricity  produced  by  the  forces 
of  the  eruption. 

Naturally  a  great  volcanic  eruption  can  cause  a  con- 
siderable loss  of  life  and  property.  When  a  large  lava 


EFFECTS  OF  ERUPTION  21 

stream  begins  to  flow  down  the  sides  of  the  mountain,  it 
cannot  be  stopped,  and  should  it  flow  toward  a  village  or 
town  it  is  likely  to  destroy  the  town  completely.  Besides 
this,  the  vegetation  of  the  country  for  many  miles  around 
is  destroyed  by  the  showers  of  red  hot  ashes  that  fall  from 
the  sky.  The  houses  of  neighboring  cities  are  similarly 
ruined  by  the  great  conflagrations  thus  set  up.  Further 
destruction  is  also  caused  by  large  streams  of  mud  that 
rush  down  the  slopes  of  the  mountain,  or  by  huge  waves 
set  up  in  the  ocean.  If  the  volcano  is  situated,  as  most 
volcanoes  are,  near  the  coast,  the  showers  of  ashes  and 
falling  stones  may  set  fire  to  vessels  in  the  neighborhood, 
or  the  progress  of  such  vessels  may  be  seriously  retarded 
by  layers  of  ashes  or  pumice  stone  that  float  on  the  sur- 
face. Sometimes  these  layers  are  so  thick  as  actually  to 
bring  ships  to  a  complete  standstill. 

It  must  not  be  supposed  that  volcanoes  are  in  a  constant 
state  of  eruption.  On  the  contrary,  nearly  all  volcanoes, 
after  an  eruption,  become  quiet  or  inactive.  The  air  soon 
clears  by  the  ashes  settling,  and  the  sunlight  again  appears. 
A  crust  forms  over  the  surface  of  the  lava,  which  rapidly 
becomes  hard  enough  to  permit  one  to  walk  over  it  safely. 
The  vegetation,  which  has  been  destroyed  by  the  hot 
ashes,  again  springs  up,  and,  if  the  volcano  happens  to  be 
situated  within  the  tropics,  where  there  is  an  abundance 
of  moisture,  the  land  soon  again  becomes  covered  by  a 
luxuriant  vegetation.  Most  of  the  people,  who  have 
escaped  sudden  death  during  the  eruption,  return  to  the 
ruins  of  their  houses;  for  it  is  a  curious  fact  that  no  matter 
how  great  has  been  a  volcanic  eruption,  or  how  far- 
reaching  the  ruin,  the  survivors,  as  a  rule,  do  not  appear 
to  hesitate  to  return  to  their  old  neighborhood.  In  a  few 
years  the  fields  are  re-cultivated,  the  villages  are  rebuilt, 
and  the  people  apparently  forget  they  are  living  over  a 


22  VOLCANOES  AND  EARTHQUAKES 

slumbering  volcano,  which  may  at  any  time  again  burst 
forth  in  a  dangerous  eruption. 

A  volcano  that  throws  out  molten  rock,  vapor  and  gases 
is  known  as  an  active  volcano.  An  active  volcano,  however, 
is  only  correctly  said  to  be  in  a  state  of  eruption  when  the 
quantity  of  the  molten  rock,  lava  or  vapor  it  throws  out 
is  greatly  in  excess  of  the  ordinary  amount. 

Sometimes  the  volcanic  activity  so  greatly  decreases 
that  the  molten  rock  or  lava  no  longer  rises  in  the  crater, 
but,  on  the  contrary,  begins  to  sink,  so  that  the  top  of 
the  lava  in  the  crater  is  often  at  a  considerable  distance 
below  its  edges.  The  lava  then  begins  to  harden  on  the 
surface,  and,  if  the  time  is  sufficient,  the  hardened  part 
extends  for  a  considerable  distance  downward.  In  this 
way  the  opening  connecting  the  crater  with  the  molten 
lava  below  becomes  gradually  closed,  the  volcano  being 
thus  shut  up,  or  corked,  just  as 'a  bottle  is  tightly  closed 
by  means  of  a  cork  driven  into  the  opening  at  its  top  so  as 
to  prevent  the  escape  of  the  liquid  it  contains. 

It  may  sound  queer  to  say  that  a  volcano  has  its 
crater  so  corked  up  as  to  prevent  the  escape  of  the  lava, 
but  the  idea  is  nevertheless  correct  and  helpful.  To 
realize  the  size  of  these  huge  volcanic  corks  one  must 
remember  that  the  craters  of  some  volcanoes  are  several 
miles  across.  A  volcano  thus  choked  or  corked  up  is  said 
to  be  extinct. 

When  we  speak  of  an  extinct  volcano  we  do  not  mean 
that  the  volcano  will  never  again  become  active.  A 
volcano  does  not  cease  to  erupt  because  there  are  no  more 
molten  materials  in  the  earth  to  escape,  but  simply  be- 
cause its  cork  or  crust  of  hardened  lava  has  been  driven 
in  so  tightly  that  the  chances  of  its  ever  being  loosened 
again  seem  to  be  very  small.  But  small  as  the  chances 
may  seem  we  must  not  forget  that  the  volcano  may  at 


EFFECTS  OF  ERUPTION  23 

any  time  become  active,  or  go  into  its  old  business  of 
throwing  out  materials  through  its  crater.  A  volcano  in 
an  extinct  condition  is  not  unlike  a  steam  boiler,  the  safety 
valve  of  which  has  been  firmly  fixed  in  place.  If  the  steam 
continues  to  be  generated  in  the  boiler,  it  is  only  a  matter 
of  time  when  the  boiler  will  blow  up,  and  the  explosion 
will  be  all  the  greater  because  the  safety  valve  did  not 
allow  the  steam  to  escape  earlier. 

Sometimes  an  intermediate  class  of  volcanoes  called 
dormant  is  introduced  between  active  volcanoes  on  the 
one  hand  and  extinct  volcanoes  on  the  other.  The  name 
dormant  volcano,  or,  as  the  word  means,  sleeping  volcano, 
is  objectionable,  since  it  might  lead  one  to  think  that  an 
extinct  volcano  is  not  sleeping  but  dead,  and  this  is  wrong. 

Since  the  plug  of  hardened  lava  in  the  volcanic  crater 
is  generally  at  a  much  lower  level  than  the  top  of  the  cra- 
ter, the  crater  will  soon  become  filled  to  a  greater  or  less 
depth  with  water,  produced  either  by  the  rain,  or  by  the 
melting  of  the  snow  that  falls  on  the  top  of  the  mountain. 
Crater  lakes,  often  of  very  great  depths,  are  common  in 
extinct  volcanoes. 

Of  course,  when  an  extinct  volcano  again  becomes 
active,  two  things  must  happen  if  the  eruption  is  explosive. 
In  the  first  place,  the  force  of  the  explosion  must  be  suffi- 
ciently great  to  loosen  the  stopper  or  plug  of  hardened 
lava  which  stops  it.  In  doing  this  the  mass  is  broken  into 
a  number  of  fragments  that  are  thrown  forcibly  upwards 
into  the  air.  After  rising  often  for  great  heights  they 
soon  fall  again  on  the  sides  of  the  mountain. 

But  besides  the  breaking  up  of  the  stopper,  the  lake  in 
the  crater  of  the  volcano  is  thrown  out  along  with  the 
cinders  or  ashes,  producing  very  destructive  flows  of  what 
are  called  aqueous  lava  or  mud  streams.  These  streams 
flow  down  the  sides  of  the  mountain,  carrying  with  them 


24  VOLCANOES  AND  EARTHQUAKES 

immense  quantities  of  both  the  ashes  thrown  out  during 
the  eruption,  or  those  that  have  collected  around  the  sides 
of  the  crater  during  previous  eruptions.  Very  frequently, 
these  streams  of  aqueous  lava  produce  greater  destruction 
than  the  molten  lava. 

If  you  have  ever  watched  common  ants  at  work  clearing 
out  or  enlarging  their  underground  homes,  in  a  piece  of 
smooth  gravel  walk  in  your  garden,  you  can  form  some 
idea  why  the  mountain  immediately  around  a  volcanic 
crater  is  conical  in  shape.  If  the  colony  of  ants  happens 
to  be  fairly  large,  you  can  see  an  almost  unbroken  stream 
of  these  industrious  little  animals,  each  bearing  in  its 
mandibles  a  small  grain  of  sand  or  gravel  brought  up 
from  some  place  below  the  surface. 

Carrying  it  a  short  distance  from  the  opening,  it  throws 
it  on  the  ground,  rapidly  returning  for  another  load.  In 
this  way  there  is  heaped  up  around  all  sides  of  the  opening 
a  pile  of  sand  or  gravel,  the  outward  slopes  of  which  gives 
the  pile  a  conical  form.  You  have,  probably,  noticed  that 
the  steepness  of  the  slopes  depends  on  the  size  of  the  grains; 
for  the  larger  these  grains  the  sharper  or  steeper  the  slopes, 
the  very  fine  grains  producing  flat  mounds  or  cones. 

It  is  the  same  with  a  volcanic  cone.  The  materials  that 
are  thrown  upwards  into  the  air,  falling  again  on  the  moun- 
tain, collect  around  the  crater  on  all  sides,  thus  giving  it 
the  characteristic  cone-like  shape  of  the  volcanic  moun- 
tain. Where  nothing  occurs  to  disturb  the  formation  of 
the  cone  its  height  above  the  level  of  the  sea  will  gradually 
increase.  Very  frequently,  however,  during  explosive 
eruptions,  a  large  part  of  this  cone  will  be  blown  away  by 
the  force  of  the  eruption  only  to  be  again  built  up  during 
some  later  eruption.  Indeed,  in  the  case  of  volcanic 
islands,  the  force  of  a  great  volcanic  eruption  is  sometimes 
so  great  that  not  only  is  a  large  volcanic  mountain  blown 


EFFECTS  OF  ERUPTION  25 

entirely  away,  but  a  hole  is  left,  where  it  had  been  stand- 
ing, that  extends  further  downwards  below  the  level  of  the 
sea  than  the  top  of  the  mountain  extended  previously 
above  it.  The  above  are  some,  but  by  no  means  all,  the 
wonders  attending  volcanic  eruptions.  We  shall  refer 
to  others  in  subsequent  chapters  in  describing  particular 
eruptions. 


CHAPTER  III 

THE  VOLCANIC  ISLAND  OF  HAWAII 

The  volcanic  island  of  Hawaii,  the  largest  of  the  Sand- 
wich Island  chain,  is  situated  in  the  mid  Pacific,  south  of 
the  Tropic  of  Cancer.  As  shown  in  Fig.  5,  this  island 
chain  consists  of  Hawaii,  Maui,  Molokai,  Oahu,  Kauai, 
Nihau,  and  about  eight  large  islands,  together  with  nu- 
merous small  islands,  extending  in  a  general  northwest 
direction  from  Hawaii  to  Nihau,  a  distance  of  about  400 
miles.  Like  most  volcanic  islands  they  lie  in  more  or  less 
straight  lines,  probably  along  fissures,  in  this  case  in  two 
nearly  parallel  lines.  The  island  of  Nihau,  however,  is  an 
exception,  the  direction  of  the  greatest  length  being  almost 
straight  across  the  two  parallel  lines. 

The  Sandwich  Islands  lie  2,000  miles  from  San  Francisco 
in  deep  water,  between  2,000  and  3,000  fathoms,  or  be- 
tween 12,000  and  18,000  feet  in  depth.  This  island  chain 
consists  of  great  volcanic  mountains,  that  had,  at  one  time, 
fifteen  active  volcanoes  of  the  first  class.  These  are  now 
all  extinct  but  three,  and  all  of  these  are  on  the  island  of 
Hawaii. 

In  his  report  to  the  United  States  Geological  Survey  for 
1882-83,  Button  states  that  the  summit  of  Mt.  Haleakala 
on  East  Maui  is  10,350  feet  above  the  sea  level.  Oahu 
has  peaks  on  its  eastern  side  2,900  feet  high,  and  peaks  on 
the  western  side  3,850  feet  high.  The  summit  of  Kauai  is 
probably  6,200  feet  above  the  sea. 

It  can  be  shown  by  deep-sea  soundings  that  all  these 
[26] 


THE  ISLAND  OF  HAWAII 


27 


From  V.  S.  Geological  Survey 

FIG.  5.  THE  HAWAIIAN  ISLANDS 


28  VOLCANOES  AND  EARTHQUAKES 

volcanic  piles  are  the  summits  of  a  gigantic  mountain 
mass  that  rises  abruptly  from  the  bed  of  the  Pacific. 
There  are  reasons  for  believing  that  this  submarine  chain 
continues  for  many  hundreds  of  miles  in  the  same  direc- 
tion beyond  Kauai. 

The  extinct  volcano,  Haleakala,  on  East  Maui  appears 
to  have  been  in  eruption  at  a  much  later  day  than  Mt. 
Kea,  which  is  also  an  extinct  volcano.  But  the  natives 
have  no  traditions  of  any  eruptions. 

The  volcanoes  on  the  other  islands  have  been  extinct 
for  a  very  long  time  judging  from  the  extent  of  their 
erosion.  Button  is  of  the  opinion  that  the  western  islands 
of  the  chain  have  been  extinct  for  much  longer  times  than 
the  remaining  islands. 

The  Sandwich  Islands,  also  known  as  the  Hawaiian 
Islands,  are  one  of  the  colonial  possessions  of  the  United 
States.  The  island  of  Hawaii  is  about  2,000  miles  from 
San  Francisco.  Honolulu,  on  the  island  of  Oahu,  the 
principal  seaport  of  the  chain,  has  a  pleasant  climate, 
and  is  an  important  coaling  station  for  warships,  com- 
mercial vessels,  whalers,  and  trading  ships  generally. 

The  principal  product  of  the  island  is  sugar  cane. 

The  island  of  Hawaii,  as  shown  in  map,  Fig.  6,  con- 
sists of  five  volcanic  mountains  and  some  small  coral  reefs. 
These  mountains  are:  Mt.  Kea,  on  the  north,  13,805 
feet  in  height;  Mt.  Haulalai,  in  the  west  central  part  of 
the  island,  8,273  feet  in  height;  Mt.  Loa,  in  the  south 
central  part  of  the  island,  13,675  feet  in  height;  Mt. 
Kilauea,  twenty  miles  east  of  the  crater  of  Loa,  4,040 
feet  high  at  the  Volcano  House,  and  4,158  feet  on  the 
highest  point  on  the  west,  and  Kohala,  5,505  feet  in 
height,  running  through  the  northwestern  part  of  the  is- 
land, and  the  Kohala  mountains  in  the  northwestern 
part. 


THE    ISLAND  OF  HAWAII 


29 


30  VOLCANOES  AND  EARTHQUAKES 

Of  these  mountains,  Mt.  Loa  and  Kilauea  are  the  only 
active  volcanoes,  aud  are  in  frequent  eruption.  Mt. 
Haulalai  was  in  eruption  during  1804.  Mt.  Kea  has  not 
been  active  during  historical  times,  while  Mt.  Kohala  has 
been  inactive  for  so  long  a  time  that  its  slopes  are  deeply 
gullied  wherever  the  rivers  flow  down  them. 

As  you  can  see  from  the  map,  Hawaii  is  very  large.  It 
has  a  length  of  ninety- three  miles  from  north  to  south, 
and  a  breadth  of  eighty  miles  from  east  to  west,  its  area 
is  about  6,500  square  miles.  With  the  exception  of  small 
patches  of  coral  reefs,  Hawaii  is  formed  entirely  of  lava, 
and  is  the  largest  pile  of  lava  in  the  world  with  the  single 
exception  of  Iceland. 

Where  the  islands  of  the  Hawaiian  chain  have  coral 
reefs  extending  off  their  coasts,  excellent  harbors  are 
found  in  the  deep  waters  between  the  islands  and  the 
reefs.  Hawaii,  however,  has  no  extended  reefs  of  this 
character,  and,  consequently,  no  first-class  harbors. 
Hilo,  on  the  eastern  coast,  is  the  best  harbor,  and  is, 
therefore,  the  principal  settlement. 

A  very  brief  examination  of  the  map  of  Hawaii  will 
show  you  that  there  are  no  rivers  on  the  island,  except  on 
the  sides  exposed  to  the  wind,  that  is,  on  the  northern 
and  northeastern  slopes.  Since  the  yearly  rainfall  on 
Hawaii  is  large,  being  in  the  neighborhood  of  a  hundred 
inches,  you  will  understand  that  considerable  rain  water 
falls  on  the  island.  In  those  parts  of  the  island  where  it 
does  not  run  off  the  surface  it  must  drain  downward 
through  the  loose  piles  of  broken  rocks  or  cinders.  A 
rainfall  of  one  hundred  inches  a  year  means  that  if  all 
the  rain  which  falls  on  each  square  foot  of  surface  was 
collected  in  a  flat  vessel  one  foot  square  with  vertical 
sides  it  would  fill  the  vessel  to  the  depth  of  one  hundred 
inches,  or  over  eight  feet.  The  drainage  of  the  rainwater 


THE  ISLAND  OF  HAWAII  31 

downwards  through  these  parts  of  the  island,  must, 
therefore,  be  large. 

Another  curious  fact  you  can  notice  on  the  map,  is  that 
the  lava  streams  of  the  past  fifty  years  from  Mt.  Loa  in- 
dicated by  heavy  dotted  lines,  in  no  cases  begin  at  the 
crater,  but  start  at  fairly  considerable  distances  from  it. 
Later  on  in  this  chapter  we  shall  explain  the  reason  for 
this  curious  fact. 

Since  practically  the  whole  of  Hawaii  has  been  formed 
from  the  streams  of  lava  that  have  flowed  at  one  time  or 
another,  you  can  understand  how  great  these  flows  must 
have  been.  But  to  do  this  fully  you  must  not  only  take 
into  consideration  the  portions  of  the  island  that  lie  above 
the  ocean  and  reach  into  the  air  at  its  greatest  height  to 
13,805  feet  above  its  surface,  you  must  also  remember 
that  this  mountain  rises  from  a  deep  ocean,  so  that  if  all 
the  water  were  removed,  you  would  see  Hawaii  towering 
up  above  the  former  level  of  the  sea  to  the  height  of  about 
31,000  feet,  or  higher  than  Mt.  Everest,  the  highest  point 
on  the  earth  above  the  present  sea  level.  This  would  be, 
approximately,  five  and  eight-tenths  miles.  You  can 
understand,  therefore,  how  great  the  flow  of  lava  must 
have  been. 

We  shall  begin  the  description  of  Hawaii  with  the  active 
volcano  of  Mt.  Loa,  or,  as  it  is  sometimes  called  in  Hawaii, 
"The  White  Mountain." 

You  will  remember  that  the  eruption  of  Krakatoa  was 
of  the  explosive  type.  Practically  no  melted  rock  or  lava 
escaped  from  the  crater.  Indeed,  if  it  had  escaped  it 
would  not  have  been  seen;  for,  not  only  the  cone  near 
the  crater,  but  also  much  of  the  mountain  itself  was  blown 
completely  out  of  sight  and  covered  by  the  waters  of  the 
ocean. 

The  eruptions  of  Mt.  Loa  are  of  an  entirely  different 


32  VOLCANOES  AND  EARTHQUAKES 

type.  In  Loa  there  are  no  explosions,  the  eruptions  being 
what  are  called  the  non-explosive  or  quiet  volcanic  erup- 
tion type.  It  will  be  necessary  to  explain  some  of  the 
peculiarities  of  this  kind  of  eruptions. 

There  is  a  great  difference  in  the  liquidity  or  the  ease 
with  which  different  kinds  of  lava  flow.  Some  lava  is  very 
thick  or  viscid,  or  is  sticky  like  thick  molasses  or  tar,  and 
therefore  flows  very  sluggishly.  Other  lava  is  thin  or 
mobile,  more  closely  resembling  water  in  the  ease  with 
which  it  flows.  Now,  in  the  case  of  a  volcanic  mountain 
of  fairly  considerable  height,  where  the  lava  possesses 
marked  liquidity,  the  lava  as  it  rises  from  great  depths 
in  the  tube  of  the  volcano  seldom  flows  over  the  top  or 
rim  of  the  crater.  This  is  not  because  the  force  that 
brings  the  lava  up  is  unable  to  carry  it  a  few  thousand 
feet  higher,  so  that  it  can  run  over  the  brim  of  the  crater, 
but  because  the  walls  of  the  volcanic  mountains  are  un- 
able to  stand  the  great  pressure  which  the  mass  of  liquid 
lava  exerts  against  their  sides. 

It  can  be  shown  that  a  column  of  liquid  lava  500  feet 
high,  will  exert  a  pressure  on  the  walls  of  the  crater  of 
about  625  pounds  to  the  square  inch.  Therefore,  in  very 
high  volcanic  mountains,  long  before  the  lava  can  reach 
the  edge  of  the  crater  and  overflow,  the  pressure  becomes 
so  great,  that  cracks  or  fissures  are  made  in  the  sides  of 
the  mountain,  through  which  the  lava  is  quietly  dis- 
charged; when,  of  course,  the  level  of  the  lava  in  the 
crater  falls  considerably.  In  volcanoes  of  the  explosive 
type,  no  matter  what  may  be  the  condition  of  lava, 
should  a  large  quantity  of  water  suddenly  find  an  entrance 
to  a  large  body  of  molten  lava  at  some  distance  below  the 
surface,  the  lava  would  be  suddenly  thrown  explosively 
into  the  air,  where  being  chilled,  it  would  afterwards  de- 
scend in  showers  of  ashes,  cinders,  or  volcanic  dust. 


THE  ISLAND  OF  HAWAII  33 

In  some  volcanic  mountains  such  as  Mt.  Loa,  the  crater, 
instead  of  being  situated  at  the  top  of  a  conical  pass  of 
ashes  or  other  material,  consists  of  a  pit-like  depression, 
generally  occupying  a  level  tract  or  plain  at  the  top  of 
the  mountain.  This  pit  is  known  as  a  caldera,  or  caldron, 
or  what  you  might,  perhaps,  call  a  huge  kettle  or  boiler. 
The  pit  has  more  or  less  vertical  sides  that  extend  down- 
wards for  unknown  depths  to  the  place  from  which  the 
lava  comes.  The  vertical  walls  of  the  caldera  are  not, 
however,  smooth,  but  exhibit  numerous  horizontal 
ledges,  that  mark  places  where  portions  of  the  floor  of 
the  caldera  were  situated  at  different  times. 

At  the  bottom  of  the  large  pit  or  caldera  on  the  summit 
of  Mt.  Loa  can  be  seen  the  level  floor  formed  of  hardened 
lava.  This  floor  is  surrounded  by  vertical  walls  on  which 
can  be  seen  the  broken  edges  of  the  old  lake  bed. 

Captain  Button,  in  a  paper  on  Hawaiian  volcanoes,  pre- 
pared for  the  United  States  Geological  Survey,  and  pub- 
lished in  its  Fourth  Annual  Report  for  1882-83,  thus  de- 
scribes the  appearance  at  the  great  crater  as  it  was  in  1882. 

"The  summit  of  Mauna  Loa  (Mt.  Loa),  is  a  broad  and 
large  platform  about  five  miles  in  length  and  four  miles 
in  width,  within  which  is  sunken  the  great  caldera  called 
Mokuaweoweo.  The  distance  from  the  point  where  we 
first  reach  the  summit  to  the  brink  of  the  pit  is  about  a 
mile  and  a  half.  The  surface  of  the  platform  is  much 
more  rugged  than  the  slopes  just  ascended.  It  is  riven 
with  cracks,  and  small  faults,1  and  piles  of  shattered  rock 
are  seen  on  every  hand.  Nowhere  is  there  to  be  seen  the 

1 A  fracture  of  a  stratum,  or  a  general  rock  mass,  with  a  relative 
displacement  of  the  opposite  sides  of  the  break. 

The  plane  or  fracture  of  a  fault,  known  as  the  fault-plane,  is 
seldom  vertical.     The  higher  side  is  called  the  heaved  or  upthrow 
side  ;  the  opposite  side  the  thrown  or  downthrow  side. 
C 


34  VOLCANOES  AND  EARTHQUAKES 

semblance  of  a  cinder  cone.  Doubtless  many  eruptions 
have  broken  forth  from  the  various  fissures  on  this  sum- 
mit, but  only  here  and  there  can  insignificant  traces  of  such 
catastrophes  be  definitely  distinguished.  The  absence  of 
fragmental  ejecta  (broken  rock  that  are  thrown  out)  is 
extraordinary.  The  shattered  blocks,  slabs,  and  spalls 
(chips)  which  everywhere  cumber  the  surface  appear  to 
have  resulted  from  the  spontaneous  shivering  and  shatter- 
ing of  the  lava  sheets  by  their  own  internal  tensions  as 
they  cooled. 

Fig.  7,  taken  from  Dutton's  report,  gives  the  general 
shape  of  this  great  caldera.  Dutton's  description  of  the 
same  is  as  follows: 

"The  length  of  the  main  caldera  is  a  little  less  than  three 
miles  and  its  width  about  a  mile  and  three-quarters.  Its 
floor,  viewed  from  above,  appears  to  be  composed  of  a 
series  of  flat  surfaces  occupying  two  distinct  levels,  the 
higher  upon  the  surface  of  the  black  ledge,  the  lower  lying 
within  the  ledge.  Upon  the  western  side  is  a  small  cinder 
cone  standing  close  upon  the  border  of  the  black  ledge. 
It  is  the  only  one  visible,  either  within  the  caldera  or  upon 
the  surrounding  summit.  Its  height  is  about  125  or  130 
feet.  It  was  seen  in  operation,  throwing  up  steam,  clots  of 
lava,  and  lapilli  (some  of  the  larger  pieces  of  fragmentary 
lava)  in  the  year  1878.  The  only  other  diversifications 
of  the  floor  are  many  cracks  which  traverse  it,  the  larger 
of  which  are  distinctly  visible  from  above.  Some  of  them 
are  considerably  faulted.  There  is  no  difficulty  in  recog- 
nizing the  fact  that  the  whole  floor  has  been  produced  by 
the  sinkage  of  the  lava  beds  which  once  continued  over 
the  entire  extent  of  the  depression,  their  undersides 
having  been  melted  off  most  probably  by  the  fires  beneath. 
The  lava  beds  in  the  immediate  vicinity  of  the  brink  upon 
the  summit  platform  wear  the  aspect  of  some  antiquity. 


THE   ISLAND  OF  HAWAII 


35 


36  VOLCANOES  AND  EARTHQUAKES 

They  have  become  brown  and  carious  by  weathering,  and, 
although  no  soil  is  generated,  little  drifts  of  gravel  are  seen 
here  and  there  mixed  with  pumice.  Since  the  caldera 
was  formed  there  is  no  indication  that  the  lavas  have 
anywhere  overflowed  its  rim.  And  yet  it  is  a  very  strange 
fact  that  within  a  half  mile,  and  again  within  a  mile  to  a 
mile  and  a  half,  lavas  have  been  repeatedly  erupted  within 
the  last  forty  years  from  the  summit  platform,  and  have 
outflowed  at  points  situated  from  700  to  900  feet  above 
the  level  of  the  lava  lake  within.  Traces  may  also  be  seen, 
at  varying  distances  back  of  the  rim,  of  very  many  erup- 
tions in  which  the  rocks  betoken  great  recency,  although 
no  dates  can  be  assigned  to  their  occurrence." 

During  his  visit  to  this  great  pit,  Captain  Dutton  suc- 
ceeded in  climbing  down  the  almost  vertical  walls  on  the 
side  of  the  crater,  and,  reaching  the  surface  of  the  hardened 
lake,  walked  over  it.  It  must  have  required  no  little 
courage  to  thus  venture  on  the  thin  floor  of  a  lake  which 
he  knew  was  rilled  to  great  depths  with  red  hot  boiling 
lava,  for  he  was  walking  over  the  surface  of  a  slumbering 
volcano,  that  might  at  almost  any  moment  awaken,  and 
opening,  swallow  him  and  his  companions.  Through 
enormous  cracks  in  the  floor,  he  could  feel  the  heat  from 
the  molten  mass,  while,  through  the  same  openings  came 
suggestive  whiffs  of  sulphur  vapor. 

During  the  eruption  of  this  mountain,  on  January  23d, 
1859,  the  light  from  the  glowing  lava  streams  was  bright 
enough  to  read  fine  print  at  Hilo,  a  distance  of  thirty-five 
miles. 

During  the  eruption  of  1852,  a  stream  of  white-hot  lava 
was  thrown  up  into  the  air  from  one  of  the  fissures  to  a 
height  of  from  300  to  400  feet. 

When  an  eruption  takes  place  in  Mt.  Loa  the  column 
of  lava  slowly  rises  in  the  crater,  threatening  to  overflow 


From  a  Stereograph,  Copyright,  by  Underwood  &  Underwood 

STONES  AND  LAVA  THROWN  UPWARDS — ERUPTION  OF  MOKUA- 
WEOWEO,  HAWAII,  JULY  4-21,  1899 


THE  ISLAND  OF  HAWAII  37 

its  lowest  edges,  but  before  this  can  take  place  the  pressure 
becomes  so  great  that  some  portion  of  the  mountain  below 
the  crater  is  fractured  and  the  lava  quietly  escapes. 

During  some  conditions  of  the  mountain  every  fifteen 
or  twenty  minutes  a  column  of  highly  glowing  lava  is 
shot  upwards  like  a  fountain  to  a  height  of  500  feet  and 
over,  falling  back  into  the  lake  in  fiery  spray.  Unusual 
heights  of  these  streams  are  generally  followed  by  an  erup- 
tion. 

These  curious  jets  of  molten  rock  certainly  cannot  be 
due  to  the  pressure  of  higher  columns  of  lava,  since  the 
crater  itself  is  near  the  top  of  a  high  plain.  They  are  be- 
lieved to  be  due  to  steam  formed  by  the  penetration  of 
the  rain  water  that  falls  on  this  part  of  the  mountain. 

You  can  now  understand  why  the  lava  streams  escaping 
from  Mt.  Loa  as  shown  on  the  map,  in  Fig.  6,  do  not 
begin  at  the  level  of  the  crater;  for  the  discharge  of  the 
lava  does  not  take  place  over  the  rim  of  the  crater,  but 
through  the  cracks  or  fissures  formed  further  down  the 
sides  of  the  mountains.  It  must  not  be  supposed,  how- 
ever, that  the  fissures  are  limited  to  the  sides  of  the  moun- 
tain where  they  can  be  seen.  They  probably  occur  in 
many  places  below  the  surface  of  the  water  on  some  part 
of  the  bed  of  the  ocean. 

The  crevices  that  are  formed  in  this  manner  in  the  sides 
of  the  mountain  vary  greatly  in  size,  some  being  so  nar- 
row that  the  lava  scarcely  flows  through  them  at  all  but 
simply  fills  up  the  crevice,  hardens  on  cooling,  and  mends 
the  cracks  in  the  mountains,  in  the  way  that  a  crack  is 
mended  in  a  piece  of  china  by  the  use  of  glue  or  in  a  wall 
of  masonry  by  mortar.  Through  the  largest  crevices  or 
cracks,  however,  large  lava  streams  may  continue  to  flow 
often  for  several  weeks,  or  even  longer. 

Sometimes,  especially  towards  the  close  of  the  eruptive 


38  VOLCANOES  AND  EARTHQUAKES 

flow,  the  lava  may  escape  disruptively,  so  that  small  cones 
are  formed  along  the  lines  of  the  fissures.  Cones  of  this 
character  are  called  lateral  cones,  and  in  the  case  of  a  vol- 
canic island,  where  the  lava  flows  out  below  the  level  of 
the  water,  the  lateral  cones  sometimes  project  above  the 
water  and  form  volcanic  islands  or  dangerous  shoals  that 
impede  navigation. 

When  the  lava  pours  out  of  a  crevice  in  the  side  of  the 
mountain,  a  river  of  molten  rock  rushes  down  the  slopes, 
at  first  like  a  torrent,  but  on  reaching  the  more  nearly 
level  ground,  it  spreads  out  in  great  lava  lakes  or  fields, 
the  surface  of  which  takes  on  the  characteristic  black 
appearance  of  basalt,  a  certain  kind  of  glass,  for  the  lavas 
of  Mt.  Loa  are  generally  basaltic.  After  an  eruption  the 
hardened  floor  of  lava  in  the  caldera,  being  no  longer  sup- 
ported by  the  liquid  mass  formerly  below  it,  falls  in,  leav- 
ing a  large  cavity  with  only  the  edges  of  the  old  floor  cling- 
ing to  the  sides  of  the  pit. 

It  will  be  interesting  to  give  a  short  account  of  some  of 
the  great  lava  streams  that  have  been  poured  out  at  differ- 
ent times  from  Mt.  Loa. 

In  the  great  eruption  of  August  llth,  1855,  the  lava 
escaped  through  fissures  from  two.  to  thirty  inches  in 
width.  Then,  flowing  in  a  continuous  stream,  it  did  not 
stop  until  it  was  within  five  miles  of  Hilo. 

In  the  eruption  of  January  23d,  1859,  the  lava  stream 
flowed  towards  the  northwest  on  the  east  side  of  Hau- 
lalai,  reaching  the  sea  in  eight  days. 

The  eruption  of  March  27th,  1868,  was  characterized  by 
severe  earthquake  shocks,  one  of  which,  occurring  on  the 
second  of  April,  destroyed  many  houses  and  produced 
huge  fissures  in  the  earth.  These  shocks  produced  great 
earthquake  waves  that  reached  distant  coasts. 

Mt.  Kilauea,  lies  at  a  lower  level  towards  the  east. 


THE  ISLAND  OF  HAWAII  39 

This  crater  is  situated  at  4,040  feet  above  the  level  of  the 
sea,  and  is  nearly  6,000  feet  below  the  caldera  on  the  top 
of  Mt.  Loa. 

Fig.  8,  taken  from  the  United  States  Geological  Sur- 
vey, Fourth  Annual  Report,  for  1882-83,  shows  a  view 
of  Kilauea  from  the  Volcano  House.  Button  gives  the 
following  description  of  the  appearance  of  Halemaumau, 
the  pit  crater  or  caldera  of  Kilauea. 

"  In  front  of  us  and  right  beneath  our  feet,  over  the  crest 
of  a  nearly  vertical  wall,  more  than  700  feet  below,  is  out- 
spread the  broad  floor  of  the  far-famed  Kilauea.  It  is  a 
pit  about  three  and  a  half  miles  in  length,  and  two  and  a 
half  miles  in  width,  nearly  elliptical  in  plan  and  surrounded 
with  cliffs,  for  the  most  part  inaccessible  to  human  foot, 
and  varying  in  altitude  from  a  little  more  than  300  feet 
to  a  little  more  than  700  feet.  The  altitude  of  the  point 
on  which  we  stand  is  about  4,200  feet  above  the  sea.  .  .  . 

"The  object  upon  which  the  attention  is  instantly 
fixed  is  a  large  chaotic  pile  of  rocks,  situated  in  the  centre 
of  the  amphitheatre,  rising  to  a  height  which  by  an  eye 
estimate  appears  to  be  about  350  to  400  feet.  From  in- 
numerable places  in  its  mass  volumes  of  steam  are  poured 
forth  and  borne  away  to  the  leeward  by  the  trade  wind. 
The  color  of  the  pile  is  intensely  black.  .  .  . 

"Around  it  spreads  out  the  slightly  undulated  floor  of 
the  amphitheatre,  as  black  as  midnight.  To  the  left  of 
the  steaming  pile  is  an  opening  in  the  floor  of  the  crater, 
within  which  we  behold  the  ruddy  gleams  of  boiling  lava. 
From  numerous  points  in  the  surrounding  floor  clouds 
of  steam  issue  forth  and  melt  away  in  the  steady  flow  of 
the  wind.  The  vapors  issue  most  copiously  from  an  area 
situated  to  the  right  of  the  central  pile,  and  in  the  southern 
portion  of  the  amphitheatre.  Desolation  and  horror  reign 
supreme.  The  engirdling  walls  everywhere  hedge  it  in. 


40  VOLCANOES  AND  EARTHQUAKES 

But  upon  their  summits,  and  upon  the  receiving  platform 
beyond,  are  all  the  wealth  and  luxuriance  of  tropical 
vegetation  heightening  the  contrast  of  the  desolation 
below.  .  .  ." 

Fig.  9  represents  the  pit-like  crater  of  Kilauea  as  it 


From  Dana's  Manual  of  Geology 

FIG.  9.  CRATER  OF  KILAUEA 

appeared  after  the  eruption  of  1886.  Here,  as  will  be  seen, 
there  are  several  lakes  of  lava,  the  largest  of  which  is 
known  as  Halemaumau.  The  eruption  of  1886,  like  all 
the  eruptions  of  Kilauea,  consisted  of  the  escape  of  the 
lava  from  an  opening  on  the  side  of  the  mountain  below 
the  crater,  and  a  sinking  in  of  the  hardened  floor  of  the 
crater.  The  figure  also  shows  the  position  of  the  New 
Lake  that  lies  east  of  Halemaumau.  The  extent  and  ap- 
pearance of  each  of  these  lakes  are  constantly  changing, 
both  as  to  height  and  area. 

Button  gives  the  following  description  of  the  appearance 
of  the  lake  of  lava,  and  some  curious  phenomena  that  occur 
on  its  surface.  He  is  describing  the  general  appearance  of 


THE  ISLAND  OF  HAWAII  41 

the  pool  of  molten  lava  covered  as  it  is  with  a  hardened 
black  crust: 

"The  surface  of  the  lake  is  covered  over  with  a  black 
solidified  crust  showing  a  rim  of  fire  all  around  its  edge. 
At  numerous  points  at  the  edge  of  the  crust  jets  of  fire 
are  seen  spouting  upwards,  throwing  up  a  spray  of  glowing 
lava  drops,  and  emitting  a  dull,  simmering  sound.  The 
heat  for  the  time  being  is  not  intense.  Now  and  then  a 
fountain  breaks  out  in  the  middle  of  the  lake  and  boils 
freely  for  a  few  minutes.  It  then  becomes  quiet,  but  only 
to  renew  the  operation  at  some  other  point.  Gradually 
the  spurting  and  fretting  at  the  edges  augment.  A  belch 
of  lava  is  thrown  up  here  and  there  to  the  height  of  five  or 
six  feet,  and  falls  back  upon  the  crust.  Presently,  near 
the  edge,  a  cake  of  the  crust  cracks  off,  and  one  edge  of  it 
bending  downwards  descends  beneath  the  lava,  and  the 
whole  cake  disappears,  disclosing  a  naked  surface  of  liquid 
fire.  Again  it  coats  over  and  turns  black.  This  operation 
is  repeated  edgewise  at  some  other  part  of  the  lake.  Sud- 
denly a  network  of  cracks  shoots  through  the  entire  crust. 
Piece  after  piece  of  it  turns  its  edge  downwards  and  sinks 
with  a  grand  commotion,  leaving  the  whole  pool  a  single 
expanse  of  liquid  lava.  The  lake  surges  feebly  for  awhile, 
but  soon  comes  to  rest.  The  heat  is  now  insupportable, 
and  for  a  time  it  is  necessary  to  withdraw  from  the  imme- 
diate brink." 

It  is  very  curious  to  think  of  cakes  of  hardened  lava 
floating  on  the  surface  of  molten  lava,  but,  of  course,  this 
is  just  as  natural  as  cakes  of  ice  floating  on  the  surface  of 
water;  for  a  cake  of  hardened  lava  is,  as  you  will  under- 
stand, only  a  cake  of  frozen  lava,  and,  being  lighter  than 
the  molten  lava,  must,  of  course,  float  on  its  surface. 

The  disappearance  of  these  cakes  of  frozen  lava  and 
their  remelting  is  still  more  curious,  and  can  be  explained 


42  VOLCANOES  AND  EARTHQUAKES 

as  follows:  The  frozen  or  solidified  mass  of  black  basalt  is 
a  trifle  lighter  than  the  lava  on  which  it  is  floating  only 
while  its  temperature  is  high,  and  therefore  expanded  by 
heat.  As  soon  as  it  cools,  its  density  increases,  and  when 
it  becomes  a  little  greater  than  that  of  the  liquid  lava,  it 
begins  to  sink  and  soon  disappears. 

Professor  Dana,  who  has  made  a  careful  study  of  the 
phenomena  of  Kilauea,  shows  in  Fig.  10,  a  cross  section  of 


From  Dana's  Manual  of  Geology 

FIG.  10.     SECTIONS  OF  KILAUEA  AT  DIFFERENT  PERIODS 

Kilauea  at  different  times.  Before  the  eruption  of  1823, 
the  depth  of  the  crater  was  from  800  to  1,000  feet.  At 
the  eruption  the  bottom  600  to  800  feet,  making  the 
depth  of  Kilauea  over  this  deeper  central  part  about 
1,500  feet.  The  varying  depths  at  different  dates  are 
clearly  marked  on  the  drawing. 

The  eruptions  of  Kilauea  generally  occur  as  follows: 
First  there  is  a  slow  rising  of  the  lava  in  the  crater. 
This  rising  continues  until  the  pressure  is  so  great  that  the 
mountain  is  ruptured  at  some  lower  place.  Next  a  dis- 
charge of  the  lava  and  a  sinking  to  a  level  in  the  conduit 
that  will  depend  on  the  position  of  the  crevice.  Then  a 
gradual  falling  in  of  the  hardened  floor  of  the  lake,  a 
portion  of  the  horizontal  walls  remaining  on  the  sides  of 
the  caldera. 

The  eruption  of  Kilauea,  however,  has  not  always  been 
of  the  quiet  type.  There  was  an  eruption  in  the  year  1789 
that  would  appear  to  have  been  of  the  explosive  variety. 
The  following  account  is  given  by  Dana  as  taken  from  a 


THE   ISLAND  OF  HAWAII  43 

history  of  the  Sandwich  Islands  by  the  Rev.  I.  Dibble, 
published  in  1843: 

"The  army  of  Keoua,  a  Hawaiian  chief,  being  pursued 
by  Kamehamoha,  were  at  the  time  near  Kilauea.  For 
two  preceding  nights  there  had  been  eruptions,  with  ejec- 
tions of  stones  and  cinders.  The  army  of  Keoua  set  out 
on  their  way  in  three  different  companies.  The  company 
in  advance  had  not  proceeded  far  before  the  ground  began 
to  shake  and  rock  beneath  their  feet,  and  it  became  quite 
impossible  to  stand.  Soon  a  dense  cloud  of  darkness  was 
seen  to  rise  out  of  the  crater,  and,  almost  at  the  same  in- 
stant, the  thunder  began  to  roar  in  the  heavens  and  the 
lightning  to  flash.  It  continued  to  ascend  and  spread 
around  until  the  whole  region  was  enveloped,  and  the 
light  of  day  was  entirely  excluded.  The  darkness  was 
the  more  terrific,  being  made  visible  by  an  awful  glare  from 
streams  of  red  and  blue  light,  variously  combined  through 
the  action  of  the  fires  of  the  pit  and  the  flashes  of  lightning 
above.  Soon  followed  an  immense  volume  of  sand  and 
cinders,  which  were  thrown  to  a  great  height,  and  came 
down  in  a  destructive  shower  for  many  miles  around.  A 
few  of  the  forward  company  were  burned  to  death  by 
the  sand,  and  all  of  them  experienced  a  suffocating  sensa- 
tion. The  rear  company,  which  was  nearest  the  volcano 
at  the  time,  suffered  little  injury,  and  after  the  earth- 
quake and  shower  of  sand  had  passed  over,  hastened  on 
to  greet  their  comrades  ahead  on  their  escape  from  so 
imminent  a  peril.  But  what  was  their  surprise  and  con- 
sternation to  find  the  centre  company  a  collection  of 
corpses!  Some  were  lying  down,  and  others  were  sitting 
upright,  clasping  with  dying  grasp  their  wives  and  chil- 
dren, and  joining  noses  (the  mode  of  expressing  affection) 
as  in  the  act  of  taking  leave.  So  much  like  life  they  looked 
that  at  first  they  supposed  them  merely  at  rest,  and  it 


44  VOLCANOES  AND  EARTHQUAKES 

was  not  until  they  had  come  up  to  them  and  handled 
them  that  they  could  detect  their  mistake."  Mr.  Dibble 
adds:  "A  blast  of  sulphurous  gas,  a  shower  of  heated 
embers,  or  a  volume  of  heated  steam  would  sufficiently 
account  for  this  sudden  death.  Some  of  the  narrators 
who  saw  the  corpses,  affirm  that  though  in  no  place  deeply 
burnt,  yet  they  were  thoroughly  scorched."  As  you  will 
see  in  Chapter  XI,  this  sudden  and  awful  death  due  to 
highly  heated  air  and  dust  particles,  caused  even  a  greater 
loss  of  life  in  the  catastrophic  eruption  of  Pelee,  in  Mar- 
tinique on  May  8,  1902. 

By  reason  of  its  situation  at  a  lower  level  on  the  slopes 
of  Mt.  Loa,  Kilauea  was  at  one  time  thought  to  be  one  of 
the  craters  lower  down  on  the  slopes  of  Loa.  This  was  the 
opinion  of  Professor  Dana  when  he  examined  the  district 
in  1840.  Since  this  time  the  region  has  been  more  care- 
fully studied,  and  Mt.  Loa  and  Kilauea,  are  now  generally 
regarded  as  separate  and  independent  volcanoes,  neither 
of  which  acts  as  a  safety  valve  for  the  other. 

We  shall  not  attempt  in  this  chapter  to  say  anything 
concerning  the  sources  or  places  from  where  these  great 
supplies  of  lava  have  been  drawn.  This  will  be  left  to 
some  subsequent  chapter,  after  we  have  described  still 
other  volcanoes. 

The  outlines  of  mountains  like  Mt.  Loa  or  Kilauea 
differ  greatly  from  mountains  like  Vesuvius;  their  slopes, 
like  the  slopes  of  all  other  Hawaii  volcanoes,  have  an 
inclination  which  does  not  exceed  10°.  The  lava  streams, 
therefore,  as  they  flow  down  the  mountains,  move  more 
slowly  than  they  would  were  the  slopes  more  precipitous, 
as  in  mountains  like  Vesuvius. 

There  have  been  many  eruptions  of  Kilauea.  That 
which  occurred  in  the  year  1840,  was  of  great  magnitude 
(see  map,  Fig.  6),  and  began  in  a  fissure  southwest  of 


THE  ISLAND  OF  HAWAII  45 

the  crater.  The  principal  eruption,  however,  broke  out 
about  twelve  miles  from  the  sea  coast,  and  about  twenty- 
five  miles  east  of  Kilauea.  Here  an  enormous  mass  of 
lava  forming  a  stream  nearly  three  miles  wide  reached 
the  ocean  at  Nanawale. 

When  an  eruption  takes  place  on  Mt.  Loa  through  a 
fissure  at  the  height  of  10,000  to  13,000  feet  the  length 
of  the  lava  streams  is  frequently  as  great  as  twenty-five 
to  thirty  miles.  Often  the  lava  though  hardening  at  the 
surface  will  continue  to  flow  underneath  through  huge  tun- 
nels, of  which  the  top  and  sides  are  composed  of  solidified 
parts  of  the  same  lava  stream.  After  the  flow  has  ceased 
long  hollow  tunnels  often  remain.  If  the  lower  end  of 
such  a  tunnel  containing  molten  lava  is  momentarily 
closed,  the  pressure  of  the  lava  above  may  not  only  burst 
through  the  obstruction,  but  may  even  throw  the  lava 
upwards  in  jets  300  to  700  feet  high.  Probably  most  of 
you  have  seen  illumined  fountains  where  jets  of  water 
are  beautifully  lighted  up  by  different  colored  electric 
lights  placed  below  them.  Such  fountains,  however, 
can  but  poorly  compare  either  in  beauty  or  grandeur 
with  these  wonderful  lava  fountains,  common  on  thfe 
slopes  of  Mt.  Loa  during  an  eruption. 


CHAPTER  IV 

THE  VOLCANIC  ISLAND   OF  ICELAND 

The  island  of  Iceland  consists  of  a  number  of  volcanic 
mountains  some  of  which  are  still  active.  As  can  be  seen 
from  the  map,  shown  in  Fig.  11,  Iceland  lies  in  the  North 
Atlantic  Ocean,  immediately  below  the  Arctic  Circle, 
about  250  miles  east  of  Greenland,  and  600  miles  west  of 
Norway.  Its  length  from  east  to  west  is  about  300  miles, 
and  its  breadth  about  200  miles,  its  total  area,  includ- 
ing the  adjacent  islands,  being  more  than  40,000  square 
miles. 

Were  all  the  water  removed  from  the  North  Atlantic 
Ocean,  it  would  be  seen  that  Iceland  rests  on  the  bed  of 
the  Atlantic,  on  a  submarine  plateau  or  highland;  for,  in 
this  part  of  th3  ocean  the  water  is  only  from  1,500  to 
3,000  feet  deep.  This  submarine  plateau  extends  as  far 
as  Norway  on  the  east,  Greenland  on  the  north,  and  the 
island  of  Jan  Mayen  on  the  northeast.  Immediately  north 
of  the  plateau  the  ocean  suddenly  drops  to  a  depth  of 
12,000  to  15,000  feet. 

Toward  the  south  the  plateau  extends  with  but  few 
interruptions  through  the  middle  of  the  ocean  to  a  shoal 
known  as  the  Dolphin  Shoal,  as  far  as  lat.  25°  N.  This 
part  of  the  ocean,  which  can  only  relatively  be  called  a 
shoal,  is  not  generally  deeper  than  9,600  feet,  although 
in  some  places  the  water  is  more  than  12,000  feet  deep. 
On  each  side  of  the  Dolphin  Shoal  the  water  is  much 
deeper,  being  in  places  15,000  feet  on  the  east,  while  on 
[46] 


THE  ISLAND  OF  ICELAND 


47 


48  VOLCANOES  AND  EARTHQUAKES 

the  west  there  are  depths  as  great  as  from  17,000  to  21,000 
feet. 

This  sunken  plateau,  possibly  including  the  shallower 
plateau  on  the  north,  is  believed  by  some  to  be  the  re- 
mains of  the  fabled  continent  of  Atlantis,  to  which  we 
shall  refer  in  another  part  of  this  book. 

The  coast  line  of  Iceland  is  unbroken  on  the  southeast, 
but  the  remainder  of  the  coast  is  deeply  indented  with 
bays  or  fiords  in  which  are  many  excellent  harbors. 

Iceland  is  liable  to  frequent  earthquake  shocks  and 
volcanic  eruptions.  From  careful  records  that  have  been 
preserved  in  the  history  of  the  island,  we  learn  that  since 
the  beginning  of  the  twelfth  century  there  have  practically 
never  been  intervals  longer  than  forty  years,  and  more 
generally  not  longer  than  twenty  years,  in  which  there  has 
not  been  a  great  earthquake  or  a  great  volcanic  eruption. 
These  volcanic  eruptions  are  often  very  protracted.  For 
example,  one  eruption  of  the  volcano  Hecla  continued  for 
six  years  without  ceasing.  Sir  Charles  Lyell,  the  great 
English  geologist,  writes  as  follows  about  Iceland: 

"Earthquakes  have  often  shaken  the  whole  island  at 
once,  causing  great  changes  in  the  interior,  such  as  the 
sinking  down  of  hills,  the  rending  of  mountains,  the  deser- 
tion of  rivers  by  their  channels,  and  the  appearance  of 
new  lakes.  New  islands  have  often  been  thrown  up  near 
the  coast,  some  of  which  still  exist,  while  others  have 
disappeared,  either  by  subsidences  or  the  action  of  the 
waves. 

"In  the  interval  between  eruptions  innumerable  hot 
springs  afford  vent  to  the  subterranean  heat,  and  solfataras 
discharge  copious  streams  of  inflammable  matter.  The 
volcanoes  in  different  parts  of  the  island  are  observed, 
like  those  of  the  Phlegraean  Fields,  Italy,  to  be  in  activity 
by  turns,  one  vent  often  serving  for  a  time  as  a  safety 


THE  ISLAND  OF  ICELAND  49 

valve  for  the  rest.  Many  cones  are  often  thrown  up  in 
one  eruption  and  in  this  case  they  take  a  linear  direction, 
running  generally  from  southeast  to  northwest." 

The  volcanic  eruptions  of  Iceland  belong  for  the  greater 
part  to  the  fissure  type.  During  a  volcanic  eruption  in 
Iceland  the  ground  is  split  in  fissures  or  cracks,  generally 
parallel  to  each  other,  and  varying  in  width  from  a  few 
inches  to  several  yards.  These  fissures  extend  for  great 
distances  across  the  country.  The  lava  quietly  wells  out 
along  the  fissures  not  unlike  the  way  quiet  spring  waters 
flow  from  their  reservoirs. 

According  to  Dr.  Th.  Thoroddsen,  the  Icelandic  geolo- 
gist, there  are  two  systems  of  fissures  extending  through 
Iceland,  from  southwest  to  northeast  in  the  southern  part 
of  the  island,  and  from  north  to  south  in  the  northern 
part.  Where  two  lines  of  fissures  cross  each  other  the 
points  of  intersection  may  be  especially  active. 

Dr.  Th.  Thoroddsen  arranges  the  volcanoes  of  Iceland 
under  three  heads,  i.  e.,  cone-shaped  volcanoes;  lava  cones; 
and  chains  of  craters,  the  last  being  the  commonest.  Out 
of  107  volcanoes  examined  by  him  in  Iceland,  eight  were 
of  the  Vesuvian  type,  or  were  built  up  of  layers  of  lava 
and  volcanic  ashes;  sixteen  were  of  the  lava-cone  type, 
similar  to  Mt.  Loa,  of  the  Hawaiian  Islands,  and  the 
remaining  eighty-three  were  of  the  type  of  crater  chains. 

The  volcano  of  Snaefell  Jokul,  4,710  feet  above  the 
level  of  the  ocean,  is  built  up  of  alternate  layers  of  lava 
and  hardened  volcanic  mud.  It  is  not,  however,  a  true 
cone-shaped  mountain. 

The  largest  volcano  in  Iceland,  the  Dyngjufkoll,  with 
its  immense  crater  of  Askja,  has  an  area  of  some  twenty- 
five  square  miles.  In  its  form  it  resembles  Snaefell. 

Volcanoes  of  the  lava-cone  type  have  been  built  up 
entirely  of  lava  and  have  a  slight  angle  of  inclination. 


50  VOLCANOES  AND  EARTHQUAKES 

These  volcanoes  range  in  size  from  small  hillocks  to  the 
largest  mountains  on  the  island.  Their  cones  generally 
stand  on  a  base  of  wide  circumference  and  frequently 
rise  to  great  heights,  the  top  being  occupied  by  a  caldera, 
or  pit  crater  like  that  on  Mt.  Loa  or  Kilauea. 

Volcanoes  of  the  type  of  chain-craters  follow  the  natural 
fissures  in  the  crust.  These  craters  are  generally  low, 
seldom  being  more  than  350  feet  high. 

There  are  also  seen  in  Iceland  caldron-shaped  depres- 
sions that  have  been  formed  by  explosive  eruptions. 
One  of  the  best  instances  of  such  craters  is  Viti,  on  the 
side  of  Mt.  Krafla.  This  crater  was  formed  by  the  sudden 
eruption  of  May  17th,  1724. 

The  lava  sometimes  quietly  runs  out  of  the  entire  length 
of  the  fissure  without  forming  any  cone.  This  was  the 
case  of  a  great  fissure  known  as  the  Eldgja  Chasm.  Here 
three  lava  streams  covered  an  area  of  270  square  miles. 

As  the  lava  comes  out  of  the  fissures,  it  generally  pro- 
duces long  ramparts  of  slags,  and  blocks  of  lava  that  are 
piled  up  on  either  side  of  the  fissure.  Sometimes  a  line 
of  low  cones  is  built  up.  These  cones  consist  of  heaps  of 
slag,  cinders,  and  blocks  of  lava.  Their  craters  are  not 
rounded  as  in  the  case  of  volcanoes  of  the  Vesuvian  type, 
but  are  oblong,  or  have  their  greatest  diameter  extending 
in  a  direction  of  the  fissure. 

Icelandic  lava  as  it  escapes  from  the  fissures  is  peculiar 
in  that  it  is  very  viscid  or  plastic  and  can  be  readily 
drawn  out  into  long  threads  that  can  be  spun  into  ropes. 
When  such  lava  runs  down  the  sides  of  a  steep  slope,  it 
often  splits  on  cooling  into  separate  blocks.  Where  it 
runs  over  flat,  level  ground,  however,  it  spreads  uniformly 
on  all  sides,  producing  vast  level  lava  deserts  that  are  as 
flat  as  the  surface  of  a  well  built  floor. 

There  are  many  rivers  in  the  north  and  the  west  of 


THE  ISLAND  OF  ICELAND  51 

Iceland.  Now,  as  the  lava  streams  flow  out  of  the  fis- 
sures they  enter  the  channels  of  the  rivers  so  that  the 
streams  of  water  must  find  new  paths  to  the  sea,  and  this 
operation  may  be  repeated  again  and  again.  Often  the 
time  between  eruptions  is  long  enough  to  give  the  rivers 
opportunity  to  cut  deep  channels  or  gorges  in  their  new 
channels;  but  on  the  next  escape  of  the  lava  these  gorges 
and  valleys  are  again  filled  with  the  molten  rock,  and  the 
rivers  must  begin  their  channel  cutting  all  over. 

You  will  note  the  frequent  use  of  the  word  Jokul,  as 
Snaefell  Jokul,  Skaptar  Jokul,  Orefa  Jokul,  etc.  The 
name  Jokul  means  a  large  mass  of  ice,  or  a  mountain 
that  is  continually  covered  with  snow,  for  example,  Snae- 
fell Jokul,  is  a  beautifully  shaped,  snow-covered  mountain 
situated  on  a  point  of  land  on  the  western  coast  of  the 
island,  extending  out  nearly  fifty  miles  into  the  sea,  be- 
tween the  Faxa  Fiord  and  the  Briela  Fiord.  It  is  a  very 
conspicuous  object,  being  visible  to  passing  ships  at  con- 
siderable distances  from  the  island.  Orefa  Jokul  is  the 
highest  mountain  in  Iceland.  Skaptar  Jokul  is  one  of  the 
active  volcanoes  of  Iceland. 

There  can  be  no  doubt  that  Iceland  has  been  formed 
entirely  by  lava  thrown  up  from  the  bottom  of  a  submarine 
plateau,  until  it  extended  above  the  surface  of  the  waters. 
To  make  an  island  entirely  of  lava  with  an  area  of 
40,000  square  miles,  must,  of  course,  have  required  many 
cones  or  craters  that  continued  to  pour  forth  lava  for 
periods  of  time  much  longer  than  those  during  which 
man  has  lived  on  the  earth. 

The  surface  of  Iceland  is  far  from  attractive.  The 
interior  is  practically  a  vast  lava  desert,  covered  with 
snow-clad  mountains  or  Jokuls.  There  is  no  plant  life 
except  in  marshy  lands  near  the  coasts,  and  even  here 
scarcely  enough  grass  is  raised  to  feed  the  few  cattle  and 


52  VOLCANOES  AND  EARTHQUAKES 

horses  owned  by  the  inhabitants.  There  is  no  agriculture, 
owing  to  the  very  short  summers,  so  that  all  grain  is 
brought  from  Europe.  Every  now  and  then  the  grass 
crop  is  destroyed  by  accumulation  of  Polar  ice  on  the 
northern  and  western  coasts.  Such  failures  are  always 
attended  by  great  famines,  when  many  of  the  people  die. 

Should  you  ever  visit  Iceland  you  would  probably  be 
surprised  to  hear  the  people  speaking  about  their  forests. 
You  might  go  over  all  the  coasts  of  the  island  without 
seeing  anything  larger  than  a  birch  bush,  not  much  higher 
than  six  feet.  These  are  what  the  Icelanders  like  to  speak 
of  as  their  forest  trees,  and  I  suppose  there  is  no  harm 
done,  if  one  only  understands  just  what  they  mean  by 
"trees." 

While,  however,  Iceland  has  practically  no  trees,  yet 
it  has  no  difficulty  in  obtaining  a  plentiful  supply  of 
timber,  since  in  the  deep  fiords  or  bays  on  the  western 
and  southern  coasts  there  can  always  be  found  much 
drift  timber  brought  there  by  the  ocean  currents  from 
the  forests  of  America. 

The  principal  town  or  settlement  in  Iceland  is  Reyk- 
javik, the  capital  of  the  island,  on  the  southwestern  coast; 
this  is  the  chief  trading  place  on  the  island.  Thingvalla 
is  also  an  important  town. 

The  lavas  that  form  the  entire  mass  of  Iceland  were 
thrown  out  both  before  and  since  the  glacial  age.  It  is 
the  opinion  of  Geikie  that  these  outflows  have  continued 
uninterruptedly  since  that  age  to  the  present  time.  It  is 
known  that  the  lavas  of  Iceland  were  thrown  out  both 
before  and  after  the  glacial  age,  because  during  the  glacial 
age,  deep  cuttings  or  groovings  were  made  on  the  surface 
of  the  earth  by  the  glaciers  as  they  slowly  moved  over  it. 
Now  lava  beds  containing  the  glacial  scratches  have  been 
found  and  resting  on  them  are  other  lava  streams.  The 


THE  ISLAND  OF  ICELAND  53 

scratched  lavas  must,  therefore,  have  been  thrown  out 
before  the  glacial  age,  and  the  second  lavas  after  that  age. 

Let  us  now  examine  some  of  the  more  active  volcanoes 
of  Iceland  and  their  eruptions.  We  will  begin  with  the 
well-known  volcano  of  Skaptar  Jokul. 

The  following  description  of  this  volcano  has  been  taken 
from  a  book  on  Iceland  by  E.  Henderson,  published  in 
Boston,  1831.  Skaptar  Jokul  lies  in  the  south  central 
part  of  Iceland  about  forty  odd  miles  from  the  coast.  It 
takes  its  name  from  the  Skaptar  River,  down  whose 
channel  the  lava  flowed  its  entire  distance  of  forty  miles 
from  the  ocean.  Skaptar  Jokul  consists  of  about  twenty 
conical  hills  lying  along  one  of  the  fissures  that  extends 
from  northeast  to  southwest. 

It  appears  from  Henderson's  account  that  people  living 
in  the  neighborhood  of  Skaptar  Jokul  were  greatly  alarmed 
by  repeated  earthquakes  that  were  felt  at  different  times 
from  the  first  to  the  eighth  of  June,  1783.  These  earth- 
quake shocks  increased  in  number  and  violence,  so  that 
the  people  left  their  homes  and  awaited  in  terror  the 
coming  catastrophe.  On  the  morning  of  the  eighth  a 
prodigious  cloud  of  dense  smoke  darkened  the  air,  and 
the  surrounding  land  soon  became  covered  with  ashes, 
pumice,  and  brimstone.  As  is  common  with  eruptions 
in  Iceland,  that  have  been  preceded  by  long  periods  of 
rest,  the  heat  produced  by  the  escaping  lava  and  the  sul- 
phurous gases,  melted  such  quantities  of  ice  that  great 
floods  were  produced  in  the  rivers. 

On  the  10th  of  June  vast  torrents  of  lava  that  had  been 
escaping  from  the  craters  entered  the  valley  of  the  Skaptar 
River,  and  commenced  flowing  through  its  channel. 
Immense  quantities  of  steam  were  produced,  and,  in  less 
than  twenty-four  hours,  the  river  was  completely  dried 
up,  for  the  lava  had  collected  in  the  channel,  which  in 


54  VOLCANOES  AND  EARTHQUAKES 

many  places  flows  between  high  rocks  from  400  to  600 
feet  in  height  and  nearly  200  feet  in  breadth,  and  had  not 
only  filled  the  river  to  its  brink,  but  had  overflowed  the 
adjacent  fields  to  a  considerable  extent,  and  flowing  along 
the  cultivated  banks  of  the  river  destroyed  all  the  farms 
in  its  path. 

On  gaining  the  outlet,  where  the  channel  of  the  Skaptar 
emerged  into  the  plain,  it  might  have  been  supposed  that 
the  burning  flood  would  have  at  once  spread  over  the  low 
fields,  which  lay  immediately  before  it,  but,  contrary  to 
all  expectations,  this  flow  was  for  a  time  stopped  by  an 
immense  unfathomed  abyss  in  the  river's  bed,  into  which 
it  emptied  itself  with  great  noise.  When  this  chasm  was 
at  last  filled,  the  lava  increased  by  fresh  flows,  rose  to  a 
prodigious  height,  and  breaking  over  the  cooled  mass, 
proceeded  south  towards  the  plain. 

In  the  meantime  the  thunder  and  lightning,  together 
with  subterranean  roars,  continued  with  little  or  no  inter- 
mission. 

On  the  18th  of  June,  1783,  another  dreadful  eruption  of 
red  hot  lava  came  from  the  volcano.  This  flowed  with 
great  velocity  and  force  over  the  surface  of  the  cooling 
stream  that  had  been  thrown  out  principally  on  the  tenth 
of  the  month.  Floating  islands  consisting  of  masses  of 
flaming  rock  were  seen  on  the  surface  of  the  lava  stream, 
and  the  water  that  had  been  banked  up  on  both  sides  of 
the  stream  was  thrown  into  violent  boiling. 

In  the  meantime  people  living  along  the  Hverfisfloit, 
the  next  largest  river  to  the  east  of  the  Skaptar,  had  not 
yet  been  visited  by  the  lava  streams.  It  is  true  that  their 
vegetation  had  been  destroyed  by  showers  of  red  hot  stone 
and  ashes,  and  that  both  atmosphere  and  water  were  filled 
with  poisonous  substances.  The  land  had  also  been 
plunged  in  utter  darkness,  so  that  it  was  scarcely  possible 


THE  ISLAND  OF  ICELAND  55 

at  noonday  to  distinguish  a  sheet  of  white  paper  held  up  at 
the  window  from  the  blackness  of  the  wall  on  either  side. 
But  the  molten  lava  streams  had  not  yet  reached  the  peo- 
ple of  this  valley  and  they  hoped  that  the  eruption  would 
soon  be  over,  and  that  the  lava  flow  would  continue  to 
follow  the  Skaptar.  On  the  3d  of  August,  however, 
they  were  alarmed  by  seeing  steam  escaping  from  the  River 
Hverfisfloit,  and  soon  all  its  water  was  dried  up,  and  a 
fresh  lava  flow  poured  down  upon  them.  As  in  the  case 
of  the  Skaptar,  the  melted  rock  completely  filled  the  empty 
channel  to  the  brink,  and  then  overflowing,  covered  the 
low  grounds  on  both  sides,  so  that  by  the  ninth  of  August 
it  had  reached  the  open  and  level  country  near  its  mouth 
and  in  the  course  of  a  few  hours  spread  itself  for  a  distance 
of  nearly  six  miles  across  the  plain.  This  flow  continued 
after  the  end  of  August,  and,  indeed,  even  as  late  as  the 
month  of  February,  1784,  when  a  new  eruption  took  place 
in  this  part  of  the  country. 

Hecla,  another  well-known  volcano  in  Iceland,  situated 
about  thirty  miles  from  the  southern  coast,  consists  of 
three  peaks,  the  central  of  which  is  the  highest.  Its  craters 
form  vast  hollows  on  the  sides  of  these  peaks,  and  at  the 
time  of  the  eruption  in  1766  were  covered  with  snow. 
Hecla  is  believed  to  have  been  an  active  volcano  long 
before  Iceland  was  inhabited.  No  less  than  twenty-three 
eruptions  have  been  recorded  between  A.  D.  1004  and  the 
great  eruption  of  1766-68. 

Volcanic  history  frequently  repeats  itself.  There  had 
been  no  great  eruption  of  Hecla  for  a  period  of  about 
twelve  years,  and  the  people  living  in  the  neighborhood 
were  congratulating  themselves  on  the  belief  that  the 
mountain  was  becoming  actually  extinct,  and  that  there- 
fore they  need  not  trouble  themselves  about  eruptions. 
Others,  however,  more  farseeing,  pointed  out  the  fact  that 


56  VOLCANOES  AND  EARTHQUAKES 

the  lakes  and  rivers  in  the  vicinity  did  not  freeze,  and  that 
the  amount  of  water  they  contained  was  greatly  decreased. 

The  following  description  of  the  great  eruption  of  Hecla 
that  was  remarkable  both  for  its  violence,  as  well  as  for 
the  time  during  which  it  continued,  is  taken  from  Syming- 
ton's "  Sketches  of  Faroe  Islands  and  Iceland  ": 

"On  the  4th  of  April,  1766,  there  were  some  slight 
shocks  of  an  earthquake,  and  early  next  morning  a  pillar 
of  sand,  mingled  with  fire  and  red  hot  stones,  burst  with  a 
loud  thundering  noise  from  its  summit.  Masses  of  pumice, 
six  feet  in  circumference,  were  thrown  to  the  distance  of 
ten  or  fifteen  miles,  together  with  heavy  magnetic  stones, 
one  of  which,  eight  pounds  weight,  fell  fourteen  miles  off, 
and  sank  into  ground  still  hardened  by  the  frost.  The 
sand  was  carried  towards  the  northwest,  covering  the 
land,  150  miles  round,  four  inches  deep,  impeding  the 
fishing  boats  along  the  coast,  and  darkening  the  air,  so 
that  at  Thingore,  140  miles  distant,  it  was  impossible  to 
know  whether  a  sheet  of  paper  was  white  or  black.  At 
Holum,  155  miles  to  the  north,  some  persons  thought  they 
saw  the  stars  shining  through  the  sand-cloud.  About 
mid-day,  the  wind  veering  round  to  the  southeast,  con- 
veyed the  dust  into  the  central  desert,  and  prevented  it 
from  totally  destroying  the  pastures.  On  the  9th  of  April, 
the  lava  first  appeared,  spreading  about  five  miles  towards 
the  southwest,  and  on  the  23d  of  May,  a  column  of  water 
was  seen  shooting  up  in  the  midst  of  the  sand.  The  last 
violent  eruption  was  on  the  5th  of  July,  the  mountains, 
in  the  interval,  often  ceasing  to  eject  any  matter;  and 
the  large  stones  thrown  into  the  air  were  compared  to  a 
swarm  of  bees  clustering  around  the  mountain-top;  the 
noise  was  heard  like  loud  thunder  forty  miles  distant, 
and  the  accompanying  earthquakes  were  more  severe  at 
Krisuvik,  eighty  miles  westward,  than  at  half  the  distance 


THE  ISLAND  OF  ICELAND  57 

on  the  opposite  side.  The  eruptions  are  said  to  be  in 
general  more  violent  during  a  north  or  west  wind  than 
when  it  blows  from  the  south  or  east,  and  on  this  occasion 
more  matter  was  thrown  out  in  mild  than  in  stormy 
weather.  Where  the  ashes  were  not  too  thick,  it  was 
observed  that  they  increased  the  fertility  of  the  grass 
fields,  and  some  of  them  were  carried  even  to  the  Orkney 
Islands,  the  inhabitants  of  which  were  at  first  terrified 
by  what  they  considered  showers  of  black  snow." 

The  largest  volcano  in  Iceland  is  Dyngjufjoll.  This  has 
on  its  summit  the  gigantic  crater  of  Askja,  some  twenty- 
five  square  miles  in  area.  This  crater  is  of  the  intermediate 
form;  the  most  general  form  of  volcanoes  on  the  island 
consisting  of  a  number  of  craters  that  closely  follow  fissures. 

Professor  Johnstrup,  in  a  report  to  the  Danish  Govern- 
ment, on  this  volcano,  states  that  the  valley  of  Askja  has 
been  gradually  filled  by  repeated  flows  of  lava  from  enor- 
mous craters  on  the  edge  of  the  mountain.  In  many  places 
the  surface  of  the  earth  is  covered  with  bright  red  pumice 
stone  that  was  thrown  out  during  an  eruption  March  29th, 
1875.  Some  of  these  craters  are  filled  with  steam  that 
escapes  with  an  almost  deafening  roar.  The  surprising 
feature  of  this  eruption  was  the  immense  quantity  of 
pumice  stone  that  escaped. 

The  volcanoes  in  the  Nyvatus  Oraefi  are  entirely  dif- 
ferent. This  barren  plain  is  thirty-five  miles  in  length 
and  thirteen  miles  in  breadth.  Suddenly  on  the  18th  of 
February,  1875,  a  volcano  appeared  in  the  centre,  and 
four  other  craters  were  formed  at  subsequent  dates.  The 
mass  of  lava  that  was  thrown  out  of  these  openings  has 
been  estimated  at  10,000,000,000,000  cubic  feet,  or  eight- 
een times  the  estimated  mass  of  lava  that  has  been 
emitted  from  Vesuvius  between  1794  and  1855.  This 
lava  is  basalt. 


CHAPTER  V 

VESUVIUS 

The  old  Greeks  and  Romans  had  but  little  knowledge 
of  volcanoes.  They  only  knew  the  volcanic  mountains  in 
the  Mediterranean  Sea.  Here  there  are  three  volcanic 
regions: — one  in  the  neighborhood  of  Naples;  one  includ- 
ing Sicily  and  the  neighboring  islands,  and  the  other  that 
of  the  Grecian  Archipelago. 

Some  idea  can  be  had  of  these  three  regions  from  a  map 
of  the  Mediterranean  shown  in  Fig.  12.  The  principal 
volcanoes  are  Vesuvius,  Etna,  Stromboli,  and  Vulcano,  a 
mountain,  by  the  way,  that  gave  its  name  to  all  volcanic 
mountains.  In  this  chapter  we  will  describe  the  volcano 
of  Vesuvius,  the  most  active,  though  by  no  means  the 
largest  of  the  volcanoes  of  the  Mediterranean. 

But,  before  doing  this,  it  will  be  well  first  to  describe 
briefly  the  volcanic  districts  surrounding  Vesuvius. 

As  shown  in  Fig.  13,  this  district  includes  Vesuvius, 
Procida,  and  Ischia. 

Ischia  is  a  small  island  measuring  about  five  miles 
from  east  to  west,  and  three  miles  from  north  to  south. 
There  were  such  terrific  volcanic  eruptions  on  this  island 
long  before  the  Christian  Era,  that  several  Greek  colonies 
were  forced  to  abandon  it.  A  colony  established  long 
afterwards,  about  380  B.  c.,  by  the  king  of  Syracuse  also 
had  to  depart.  Strabo,  the  Grecian  geographer  (born 
about  63  B.  c.),  states  that,  according  to  tradition,  terrific 
earthquakes  occurred  on  the  island  a  little  before  his  time, 
[58] 


VESUVIUS 


59 


60 


VOLCANOES  AND  EARTHQUAKES 


and  its  principal  mountain  threw  out  large  quantities  of 
molten  rock,  which  flowed  into  the  sea.    At  the  time  of 


VOLCANIC  DISTRICT 
OF 

NAPLES. 


diCampantllo 


FIG.  13.    THE  VOLCANIC  DISTRICT  AROUND  VESUVIUS 

this  eruption  there  were  earthquake  waves  in  the  sea, 
the  waters  of  which  slowly  receded,  leaving  large  portions 
of  the  bottom  uncovered,  and  rushing,  afterwards,  vio- 
lently over  the  land,  caused  great  destruction.  It  was 
during  this  disturbance,  so  Strabo  asserts,  that  the  island 
of  Procida  was  formed  by  being  violently  torn  from 
Ischia. 

The  Phlegraean  Fields  was  a  name  given  by  the  ancients 
to  some  of  the  lowlands  in  the  neighborhood  of  Naples; 
they  were  believed  to  be  under  the  special  protection  of 
the  Roman  gods.  When  the  frequent  earthquake  shocks 
shook  these  fields,  the  Roman  people  believed  that  con- 
flicts were  taking  place  between  their  gods  and  slumbering 
giants  confined  in  the  regions  below  the  surface. 


VESUVIUS  61 

It  is  more  than  probable  that  Mt.  Vesuvius  has  always 
been  the  centre  of  these  volcanic  disturbances.  Long 
before  the  Christian  Era,  however,  Vesuvius,  or  Somma, 
the  name  given  to  the  old  crater  that  then  occupied  the 
summit  of  the  mountain,  had  been  an  extinct  crater. 
Indeed,  it  had  been  so  quiet  that  the  people  who  lived  on 
its  slopes  did  not  appear  to  knovv  they  were  living  on  the 
slopes  of  a  slumbering  volcano.  Their  knowledge  of  vol- 
canic mountains  must  have  been  very  limited,  for  this 
mountain  with  the  huge  pit  at  its  summit  had  all  the  ap- 
pearance of  a  volcanic  crater.  When  they  climbed  to  the 
top  of  the  mountain,  which,  of  course,  they  frequently 
did  to  look  after  the  vineyards  they  were  cultivating  on 
the  slopes,  and  looked  down  into  the  deep  pit  from  the 
rocks  on  its  edge,  they  could  see  at  the  bottom  of  a  great 
central  pit  three  miles  in  diameter,  a  lake,  with  room 
here  and  there  to  enable  one  to  walk  along  its  borders. 
The  walls  of  the  precipice  were  covered  with  luxuriant 
vines. 

When  we  say  that  none  of  the  people  even  suspected 
that  Vesuvius  had  ever  been  in  a  state  of  eruption,  we 
must  except  some  of  their  learned  men.  For  both  Dio- 
dorus  Siculus,  a  native  of  Sicily,  who  lived  about  10  B.  c., 
and  wrote  an  Universal  History,  containing  some  forty 
volumes,  of  which  only  about  one-third  remain,  and 
Strabo,  the  Geographer,  pointed  out  in  a  general  manner, 
that  Vesuvius,  and  much  of  the  surrounding  country, 
looked  as  if  it  had  been  eaten  by  fire.  Then,  too,  a  Roman 
philosopher  who  lived  between  A.  D.  1  and  A.  D.  64,  spoke 
of  Vesuvius  being  "a  channel  for  the  eternal  fire!" 

Let  us  now  endeavor  to  obtain  some  idea  of  the  appear- 
ance of  this  region  a  short  time  before  A.  D.  79,  when  Vesu- 
vius burst  forth  in  a  terrific  eruption.  The  slopes  of  the 
mountain  were  covered  with  the  rich  vegetation  that 


62  VOLCANOES  AND  EARTHQUAKES 

characterizes  this  part  of  Italy.  When  most  volcanic 
ashes  and  lava  have  been  exposed  for  some  time  to  the 
atmosphere  they  make  a  very  fertile  soil.  Now,  this  soil 
on  the  slopes  of  Vesuvius  made  the  vineyards  that  covered 
the  mountain  slopes  and  the  fields  for  miles  around  its 
base,  bear  very  plentifully,  so  that  the  people  lived  very 
comfortably.  Here  and  there  on  the  slopes  of  the  moun- 
tain large  towns  like  Herculaneum  and  Pompeii  had 
.long  been  established,  while,  in  the  distance,  was  the  large 
city  of  Naples.  Besides  these  there  were  numerous  popu- 
lous towns  and  villages  scattered  here  and  there  over  the 
plain  or  on  the  lower  mountain  slope. 

You  have  all  probably  read  of  the  Roman  gladiator, 
Spartacus.  Spartacus  was  a  Thracian  by  birth,  and  while 
a  shepherd  had  been  taken  prisoner  by  the  Romans  and 
sold  to  a  trainer  of  gladiators  at  Capua.  Chaffing  under 
the  tyranny  of  the  Romans,  who  forced  him  to  fight  in 
the  arena  with  men  and  beasts,  he  revolted  against  his 
masters,  and  with  a  band  of  some  seventy  followers,  fled 
to  a  mountain  fastness  in  the  crater  of  Vesuvius.  Proud 
Rome  sent  a  few  men  to  recapture  him,  with  scourges 
for  his  punishment,  but  they  were  beaten  by  Spartacus. 
Every  day  dissatisfied  men  like  himself  escaped  from 
the  Romans  and  joined  his  ranks.  Rome  sent  a  larger 
body  of  men  against  Spartacus,  but  they  also  were  beaten. 
At  last,  recognizing  the  gravity  of  the  position,  the  Roman 
Praetor,  Clodius,  was  sent  against  Spartacus  with  an  army 
of  some  three  thousand  men.  Clodius  caught  Spartacus 
in  the  crater  and  guarded  the  only  space  by  which  it 
seemed  possible  for  Spartacus  to  escape.  Using  the  vines 
that  covered  the  precipitous  walls  of  the  crater,  Spartacus 
did  escape,  and  falling  unexpectedly  on  the  armies  of 
Clodius,  routed  them.  After  this  victory,  Spartacus  with 
an  army  of  over  100,000  men  overran  southern  Italy, 


VESUVIUS  63 

and  sacked  many  of  the  cities  of  the  Roman  Campania. 
During  this  time  Spartacus  defeated  one  Roman  army 
after  another,  until  finally,  in  the  year  71  B.  c.,  Crassus 
was  sent  against  him  and  vainly  endeavored  to  conquer 
him.  Being  unsuccessful,  Crassus  urged  the  Roman 
Senate  to  recall  Lucullis  from  Asia  and  Pompey  from 
Spain,  and  finally  poor  Spartacus  was  cut  down  in  a  fight 
he  made  against  Crassus  and  Lucullis. 

But  let  us  come  to  the  great  eruption  of  Vesuvius  in 
A.  D.  79.  The  people  living  on  the  slopes  of  Vesuvius 
were  not  without  plenty  of  warnings  of  the  dreadful 
catastrophe  that  was  coming.  As  early  as  A.  D.  63  there 
was  a  great  earthquake  that  shook  the  country  far  beyond 
Naples.  In  Pompeii,  then  a  flourishing  city,  the  Temple 
of  Isis  was  so  much  damaged  that  it  had  to  be  rebuilt. 

Even  if  the  earthquake  shocks  had  not  foretold  the 
coming  eruption,  there  were  other  signs.  The  height  of 
wrater  in  the  wells  decreased.  Springs  that  had  never 
before  been  known  to  fail,  dried  up  completely.  These 
changes,  as  we  well  know,  were  due  to  the  red  hot  lava 
being  slowly  forced  up  from  great  depths  into  the  tube 
connected  with  the  crater. 

The  earthquake  shocks  continued  at  irregular  intervals 
for  sixteen  years,  until,  on  the  25th  of  August,  A.  D.  79, 
about  one  o'clock  in  the  afternoon,  Vesuvius  burst  forth 
in  the  terrible  eruption  that  destroyed  the  towns  of  Pom- 
peii and  Herculaneum.  Pompeii  was  a  seaport  town 
situated  near  the  mouth  of  the  River  Sarno,  about  fifteen 
miles  southeast  of  Naples.  It  was  a  beautiful  place, 
containing  many  splendid  temples.  Its  people  for  the 
greater  part  lived  luxuriously,  for  Pompeii  was  the  sum- 
mer resort  of  the  richer  people  of  Naples,  some  of  whom 
lived  there  during  the  hottest  months  of  the  year. 

Herculaneum,  the  other  town,  was  nearer  Naplgs,  only 


54  VOLCANOES  AND  EARTHQUAKES 

five  miles  from  the  city.  It  was  also,  like  Pompeii,  a 
beautiful  town,  and  contained  many  splendid  buildings. 
In  each  town  there  were  magnificent  baths  and  a  large 
theatre.  The  inhabitants  spent  so  much  of  their  time  in 
the  open  air,  or  in  the  baths,  that  it  was  not  necessary 
for  them  to  build  very  large  houses.  The  houses,  however, 
were  well  built,  and  though  generally  consisting  of  prac- 
tically a  single  story,  were  provided  with  all  the  luxuries 
that  great  wealth  could  command. 

On  August  25th,  A.  D.  79,  severe  earthquake  shocks 
again  visited  this  part  of  the  world  and  Vesuvius  suddenly 
threw  up  from  its  crater  an  immense  column  of  black 
smoke,  which,  rising  high  in  the  air,  spread  out  in  the  form 
of  a  huge  mushroom,  or,  perhaps,  more  like  the  umbrella 
pine  tree  of  the  neighborhood.  Rapidly  spreading  on  all 
sides,  the  smoke  soon  completely  shut  out  the  light  of 
the  sun,  and  wrapped  the  earth  in  an  inky  darkness, 
except  for  a  red  glare  from  columns  of  molten  rock  that 
rushed  out  of  the  crater. 

From  the  dark  cloud  immense  quantities  of  red  hot 
stones,  pumice,  and  volcanic  ashes  descended  on  the 
earth.  At  the  same  time  there  fell  a  deluge  of  rain,  caused 
by  the  sudden  condensation  of  the  enormous  amount  of 
water  vapor  that  was  thrown  out  from  the  crater  during 
the  eruption.  Fortunately,  very  few  of  the  people  were 
killed  in  either  of  the  cities  of  Pompeii  and  Herculaneum, 
although  some  bodies  were  found  in  the  ruins.  Most  of 
the  people  escaped  through  the  darkness  and  gloom, 
continuing  to  flee  from  the  city  for  at  least  three  days. 

Both  cities  were  covered  so  deep  with  ashes  or  mud  that 
the  tops  of  the  tallest  buildings  were  no  longer  visible. 
Pompeii  was  buried  by  showers  of  ashes  or  volcanic  cin- 
ders, and  Herculaneum  mainly  by  vast  floods  of  aqueous 
lava.  . 


VESUVIUS  65 

So  completely  were  these  cities  covered  that  their  very- 
existence  was  at  last  forgotten.  It  is  true  that  Titus,  who 
was  then  Emperor  of  Rome,  endeavored  to  clear  away 
the  ashes  and  rebuild  Pompeii,  but  the  task  was  so  great 
that  he  finally  abandoned  it. 

During  the  year  1592,  the  architect  Fontana,  while 
superintending  the  building  of  an  aqueduct,  came  across 
some  ancient  buildings.  At  a  much  later  date,  in  1713, 
some  workmen,  while  digging  a  well  in  the  village  of  Por- 
tici,  uncovered  three  marvellously  beautiful  marble  stat- 
ues. In  the  year  1738,  the  same  well  was  dug  deeper, 
when  traces  of  the  old  theatre  of  Herculaneum  were  dis- 
covered. Some  effort  was  then  made  to  excavate  the  city 
and  many  of  the  public  buildings  and  private  houses  were 
uncovered,  and  statues,  mosaics,  wall  paintings,  and 
charred  manuscripts  of  papyrus  were  found.  A  few  of 
these  have  been  unrolled  and  deciphered,  but  owing  to 
the  difficulty  of  doing  this,  without  destroying  them, 
the  greatest  number  still  remain  unread. 

In  1860,  the  Italian  Government  began  a  systematic 
excavation  of  the  buried  cities,  and  now  both  Pompeii 
and  Herculaneum  are  thrown  open  to  the  sunlight  so 
that  one  can  walk  through  the  old  streets,  and  look  into 
the  houses,  in  which,  before  A.  D.  79,  the  people  lived  so 
happily. 

Many  interesting  stories  are  told  about  the  discoveries 
that  were  made  during  the  government  excavations. 
The  skeleton  of  one  of  the  inhabitants  was  found  grasping 
a  money  bag.  He  might  have  escaped,  but  had  gone 
back  to  get  his  money.  He  got  it,  but  remained  with  it. 
In  another  place,  the  skeletons  of  a  number  of  people 
were  found  in  an  underground  room  or  cellar  of  a  house, 
where  were  also  found  some  mouldy  bread  and  empty 
water  flasks.  Instead  of  leaving  the  city,  which  they  might 


66  VOLCANOES  AND  EARTHQUAKES 

have  done,  they  had  retreated  to  the  underground  room 
for  safety,  but  the  fine  volcanic  dust  drifted  in  and  suffo- 
cated them. 

The  younger  Pliny,  the  historian,  has  given  an  excellent 
account  of  some  features  of  this  great  eruption.  It  ap- 
pears that  his  uncle  was  stationed  with  the  Roman  fleet, 
in  the  Bay  of  Naples,  at  the  time  of  the  eruption.  He 
describes  the  dark  cloud  of  ashes  that  was  formed  over 
Vesuvius.  He  refers  to  the  rapidity  with  which  it  spread, 
and  to  the  showers  of  ashes,  cinders,  and  stones  that  it 
rained  down  on  the  earth.  His  uncle,  the  elder  Pliny, 
landed  on  the  coast,  and  was  afterwards  killed  by  a  cloud 
of  sulphurous  vapor  that  swept  down  the  side  of  the 
mountain. 

The  following  letter  from  the  younger  Pliny,  describing 
his  flight  with  his  mother  from  Misenum,  is  quoted  from 
Dana's  "Characteristics  of  Volcanoes." 

"It  was  now  seven  o'clock  [on  the  morning  of  Au- 
gust 25th],  but  the  light  was  still  faint  and  doubtful. 
The  surrounding  buildings  had  been  badly  shaken,  and 
although  we  were  in  an  open  spot  [a  little  yard  between 
his  uncle's  house  and  the  sea],  the  space  was  so  small 
that  the  danger  of  a  catastrophe  from  falling  walls  was 
great  and  certain.  Not  till  then  did  we  make  up  our 
minds  to  go  from  the  town.  .  .  .  When  we  were  free  from 
the  buildings  we  stopped.  There  we  saw  many  wonders 
and  endured  many  terrors.  The  vehicles  we  had  ordered 
to  be  brought  out  kept  running  backward  and  forward, 
though  on  level  ground;  and  even  when  blocked  with 
stones  they  would  not  keep  still.  Besides  this,  we  saw 
the  sea  sucked  down  and,  as  it  were,  driven  back  by  the 
earthquake.  There  can  be  no  doubt  that  the  shore  had 
advanced  on  the  sea,  and  many  marine  animals  were  left 
high  and  dry.  On  the  other  side  was  a  dark  and  dreadful 


VESUVIUS  67 

cloud,  which  was  broken  by  zigzag  and  rapidly  vibrating 
flashes  of  fire,  and  yawning  showed  long  shapes  of  flame. 
These  were  like  lightning,  only  of  greater  extent.  .  .  . 

"  Pretty  soon  the  cloud  began  to  descend  over  the  earth 
and  cover  the  sea.  It  enfolded  Caprese  and  hid  also  the 
promontory  of  Misenum."  .  .  .  The  flight  was  continued. 
"  Ashes  now  fell,  yet  still  in  small  amount.  I  looked  back. 
A  thick  mist  was  close  at  our  heels,  which  followed  us, 
spreading  out  over  the  country,  like  an  inundation."  .  .  . 
Turning  from  the  roar  in  order  to  avoid  the  fleeing, 
terror-stricken  throng,  they  rested.  "  Hardly  had  we  sat 
down  when  night  was  over  us — not  such  a  night  as  when 
there  is  no  moon  and  clouds  cover  the  sky,  but  such  dark- 
ness as  one  finds  in  close-shut  rooms.  One  heard  the 
screams  of  women,  the  fretting  cries  of  babes,  and  shouts 
of  men.  .  .  . 

"Little  by  little  it  grew  light  again.  We  did  not  think 
it  the  light  of  day,  but  a  proof  that  the  fire  was  coming 
nearer.  It  was  indeed  fire,  but  it  stopped  afar  off;  and 
then  there  was  darkness  again,  and  again  a  rain  of  ashes, 
abundant  and  heavy,  and  again  we  rose  and  shook  them 
off,  else  we  had  been  covered  and  even  crushed  by  the 
weight.  ...  At  last  the  murky  vapor  rolled  away,  in 
disappearing  smoke  or  fog.  Soon  the  real  daylight  ap- 
peared; the  sun  shone  out,  of  a  lurid  hue,  to  be  sure,  as  in 
an  eclipse.  The  whole  world  which  met  our  frightened 
eyes  was  transformed.  It  was  covered  with  ashes  white 
as  snow." 

Young  Pliny  and  his  mother  returned  to  Misenum, 
and  survived  the  perils  to  which  they  were  exposed. 

It  was  during  this  eruption  that  a  large  part  of  the  old 
crater  was  blown  off  the  mountain  by  the  tremendous  force 
at  work. 

There  have  been  many  eruptions  of  Vesuvius  since  the 


68  VOLCANOES  AND  EARTHQUAKES 

great  eruption  of  A.  D.  79.  One  of  these  occurred  during 
the  reign  of  Severus,  A.  D.  203.  It  was  during  this  erup- 
tion that  an  additional  part  of  the  old  crater  of  Somma 
was  blown  away. 

Another  great  eruption  occurred  A.  D.  472.  Then  great 
quantities  of  volcanic  dust  were  thrown  up  into  the  air, 
and  falling,  covered  practically  all  parts  of  Europe,  pro- 
ducing darkening  of  the  sun  and  great  fear  as  far  as  the 
city  of  Constantinople. 

But  what  was  perhaps  a  still  greater  eruption  occurred 
during  December  of  1631.  This  eruption  spread  great 
quantities  of  ashes  over  the  country  for  hundreds  of  miles 
around,  and  great  streams  of  mud  rushed  down  the  slopes 
of  the  mountain.  Buccini  gives  the  following  account  of 
this  eruption: 

"The  crater  was  five  miles  in  circumference,  and  about 
1,000  paces  deep.  Its  sides  were  covered  with  brushwood, 
and  at  the  bottom  there  was  a  plain  on  which  cattle 
grazed.  In  the  woody  parts  wild  boars  frequently  har- 
bored. In  one  part  of  the  plain,  covered  with  ashes,  were 
three  small  pools,  one  filled  with  hot  but  bitter  water; 
another  with  water  salter  than  the  sea,  and  a  third  with 
water  that  was  hot  but  tasteless.  But  at  length  these 
forests  and  grassy  plains  were  consumed,  being  suddenly 
blown  into  the  air  and  their  ashes  scattered  to  the  winds. 
In  December,  1631,  seven  streams  of  lava  poured  at  once 
from  the  crater  and  overflowed  several  villages,  on  its 
flanks,  and  at  the  foot  of  the  mountain.  Reisna,  partly 
built  over  the  ancient  city  of  Herculaneum,  was  consumed 
by  the  fiery  torrent.  Great  floods  of  mud  were  as  destruc- 
tive as  lava.  This  is  no  unusual  occurrence  during  these 
catastrophes  for  such  is  the  violence  of  the  rains  produced 
by  the  evolution  of  aqueous  vapors  that  torrents  of  water 
descend  the  cone  and  become  charged  with  impalpable 


VESUVIUS  69 

volcanic  dust,  and  rolling  among  ashes,  acquire  sufficient 
consistency  to  deserve  the  ordinary  appellation  of  aqueous 
lava." 

Of  course,  you  will  understand  that  we  have  given  only 
a  few  of  the  most  notable  of  the  eruptions  of  Mt.  Vesuvius. 
Since  the  year  A.  D.  1500  there  have  been  no  less  than 
fifty-six  recorded  eruptions,  that  of  the  year  1857  being 
especially  violent. 

Omitting  these  eruptions  we  at  last  come  to  the  great 
recent  eruption  of  1872. 

Fortunately,  the  eruption  of  1872,  as  well  as  still  more 
recent  eruptions  that  have  occurred,  have  been  more 
accurately  described  than  have  most  volcanic  eruptions, 
for  the  Italian  Government,  recognizing  the  value  to  the 
natives  of  Italy  of  a  knowledge  of  what  was  going  on  at 
the  crater  of  Vesuvius,  has  maintained  for  the  past  thirty 
years  an  observatory  on  the  western  part  of  the  mountain. 
This  observatory  has  been  placed  in  charge  of  Prof.  Luigi 
Palmieri,  a  well-known  student  of  volcanoes  and  earth- 
quakes. At  this  place  records  are  kept  of  the  behavior 
of  the  volcano,  of  all  earthquake  disturbances,  as  well  as 
other  phenomena.  At  the  same  time,  by  the  use  of  pho- 
tography, excellent  pictures  have  been  obtained  showing 
the  appearance  of  the  sky  during  an  eruptiqn. 

Vesuvius  had  been  in  a  quiet  state  from  November, 
1848,  to  the  year  1871,  when  small  quantities  of  lava 
flowed  continuously  for  several  months.  Again,  early  in 
1872,  other  quiet  eruptions  of  lava  continued  for  weeks 
at  a  time.  Finally,  on  April  26th,  of  that  year,  a  violent 
explosive  eruption  occurred.  The  following  account  has 
been  taken  from  Palmieri 's  report,  entitled,  "The  Erup- 
tion of  Vesuvius  in  1872." 

On  April  23d  the  recording  earthquake  instruments, 
the  seismographs,  were  greatly  affected.  On  the  evening 


70  VOLCANOES  AND  EARTHQUAKES 

of  the  24th  lava  streams  flowed  down  the  cone  in  various 
directions.  These  streams  were  continued  on  the  25th 
and  the  26th,  so  that  on  the  night  of  the  26th  the  observa- 
tory lay  between  two  streams  of  molten  lava  that  threw  out 
so  much  heat  that  the  glass  windows  in  the  observatory 
were  cracked,  and  a  scorching  smell  was  quite  perceptible 
in  the  rooms.  The  cone  of  the  mountain  was  deeply  fis- 
sured, lava  escaping  freely  from  all  the  fissures,  so  that 
the  molten  rock  appeared  to  ooze  from  over  its  entire  sur- 
face, or  as  Palmieri  expressed  it,  "Vesuvius  sweated  fire." 

This  great  cracking  or  fissuring  of  the  cone  was  accom- 
panied by  the  opening  of  two  large  craters  at  the  summit, 
that  discharged,  with  a  great  noise,  immense  clouds  of 
steam,  dust,  lapilli,  and  volcanic  bombs.  These  latter 
are  very  curious  and  consist  of  masses  of  soft  lava  that  are 
thrown  high  into  the  air  by  the  outrushing  columns  of 
steam.  Being  rotated  or  spun,  as  they  rise  in  the  air, 
they  assume  a  spherical  shape.  Some  of  these  volcanic 
bombs  were  thrown  to  a  height  estimated  by  Palmieri  to 
have  been  nearly  4,000  feet  above  the  top  of  the  mountain. 
When  the  height  of  a  projectile  is  known,  the  velocity  with 
which  it  left  the  opening  from  which  it  was  projected  or 
thrown  can  be  estimated,  so  that  the  volcanic  bombs 
must  have  left  the  crater  at  a  velocity  of  about  600  feet 
per  second. 

On  the  27th,  in  the  evening,  the  lava  streams  ceased 
flowing,  but  the  dust  and  lapilli  continued  to  fall  during 
the  28th  and  the  29th.  On  the  30th  the  detonations  de- 
creased and  by  the  1st  of  May  the  eruption  was  entirely 
over. 

Palmieri  calculated  that  the  quantity  of  molten  rock 
thrown  out  during  this  eruption  was  sufficient  to  cover  an 
area  of  about  1.8  square  miles  to  an  average  depth  of 
about  thirteen  feet. 


VESUVIUS  71 

As  we  can  see  from  the  above  descriptions,  the  volcanic 
activity  of  Vesuvius  is  characterized  by  long  periods  of 
rest  followed  by  periods  of  activity.  The  periods  of  rest 
are  measured  by  years,  and  often  by  centuries;  the  pe- 
riods of  activity  by  days  or  hours. 

But  Vesuvius  was  not  to  have  a  long  period  of  rest  after 
its  eruption  of  1872.  On  the  contrary,  shortly  after  the 
great  disaster  of  Martinique  in  1906,  it  again  became  ac- 
tive, and  on  the  5th  of  April,  1906,  began  throwing  large 
blocks  of  lava  out  of  its  central  cone,  and  on  the  next 
day  began  to  throw  out  large  streams  of  lava,  which,  on 
April  7th,  destroyed  a  village  in  the  neighborhood.  At 
the  same  time  rumbling  sounds  were  heard,  and  violent 
earthquake  shocks  shattered  the  windows  of  the  houses. 

Professor  Matteucci,  the  present  director  of  the  Vesuvius 
Observatory,  made  the  following  report  on  April  the  8th. 

"The  eruption  of  Vesuvius  has  assumed  extraordinary 
proportions.  Yesterday  and  last  night  the  activity  of 
the  crater  was  terrific,  and  is  increasing.  The  neighbor- 
hood of  the  observatory  is  completely  covered  with  lava. 
Incandescent  rocks  are  being  thrown  up  by  the  thousands, 
to  a  height  of  2,400  feet  or  even  3,000  feet,  and  falling 
back  form  a  large  cone.  Another  stream  of  lava  has  ap- 
peared. .  .  .  The  noise  of  the  explosion  and  of  the 
rocks  striking  together  is  deafening.  The  ground  is  shaken 
by  strong  and  continuous  seismic  movements,  and  the 
seismic  instruments  [instruments  employed  to  record  the 
time,  direction,  and  intensity  of  earthquake  movements] 
threaten  to  break.  It  will  probably  be  necessary  to  aban- 
don the  observatory,  which  is  very  much  exposed  to  the 
shocks.  The  telegraph  is  interrupted,  and  it  is  believed 
the  Funicular  railroad  has  been  destroyed." 

On  April  9th  Matteucci  made  the  following  report: 

"The  explosive  activity  of  Vesuvius,  which  was  so  great 


72  VOLCANOES  AND  EARTHQUAKES 

yesterday,  and  was  accompanied  by  very  powerful  elec- 
tric discharges,  diminished  yesterday  afternoon.  During 
the  night  the  expulsion  of  rocks  ceased,  but  the  emission 
of  sand  increased,  completely  enveloping  me  and  forming 
a  red  mass  from  six  to  ten  centimeters  deep,  which  carried 
desolation  into  these  elevated  regions.  Masses  of  sand 
gliding  along  the  earth,  created  complete  darkness  until 
seven  o'clock.  Several  blocks  of  stone  broke  windows  in 
the  observatory.  Last  night  the  earthquake  shocks  were 
stronger  and  more  frequent  than  yesterday,  and  displaced 
the  seismic  apparatus.  Yesterday  afternoon  and  this 
morning,  torrents  of  sand  fell." 

On  April  10th  Matteucci  sent  the  following  report: 

"Last  night  was  calm,  except  for  a  few  explosions  of 
considerable  force  from  time  to  time.  At  four  o'clock  this 
morning  the  explosions  became  more  violent.  The  seismic 
instruments  recorded  strong  disturbances." 

The  eruption  of  Vesuvius  of  1906  was  especially  noted 
for  the  great  quantities  of  sand  and  ashes  thrown  out  of 
the  crater.  The  amount  of  sand  that  fell  on  the  roof  of 
the  market  house  at  Monti  Olivetto  was  so  great  that  the 
roof  fell  in.  In  this  eruption  there  were  some  six  lava 
streams  that  poured  down  the  mountain.  The  most  for- 
midable of  these  was  that  which  descended  towards 
Torre  Annunziata.  Here  it  stopped  just  short  of  the  wall 
of  the  cemetery  outside  of  the  town. 

During  this  eruption  of  Vesuvius,  as  in  previous  erup- 
tions, clouds  of  volcanic  dust  collected  in  the  air,  shutting 
off  the  light  of  the  sun.  Naples  was  in  a  state  of  semi- 
darkness.  The  roofs  of  the  houses  were  covered  to  a  depth 
of  several  inches  with  an  exceedingly  fine  reddish  dust. 
In  some  places  this  dust  had  drifted  into  heaps  fully  a 
yard  in  depth. 


CHAPTER  VI 

OTHER  VOLCANOES  OF  THE  MEDITERRANEAN 

The  relative  positions  of  the  other  volcanic  mountains 
of  the  Mediterranean  Sea;  i.  e.,  Etna,  Stromboli,  and  the 
volcanoes  of  the  Santorin  group  of  the  Grecian  Archi- 
pelago, are  shown  in  the  map,  Fig.  12. 

We  will  begin  with  the  volcanic  mountain  of  Etna, 
under  which,  according  to  mythology,  the  angry  gods 
had  buried  the  rebellious  Typhoon. 

Etna  is  situated  on  the  island  of  Sicily,  immediately 
southwest  of  Italy.  It  is  a  much  larger  mountain  than 
Vesuvius,  rising,  as  it  does,  from  a  circular  base  about 
eighty-seven  miles  around,  to  a  height  of  10,840  feet 
above  the  level  of  the  Mediterranean.  It  forms  a  con- 
spicuous object  when  seen  either  from  the  Mediterranean, 
or  from  distant  parts  of  Italy. 

The  height  of  Etna  is  so  great  that  its  slopes  can  be 
divided  into  three  distinct  climatic  zones  or  belts.  The 
lowest  of  these  lies  between  the  sea  and  a  height  of 
2,500  feet.  In  this  zone  the  mountain  slopes  are  covered 
with  cultivated  fields,  olive  groves,  orchards,  and  vine- 
yards. The  middle  zone  lies  between  2,500  feet  and  6,270 
feet.  This  zone  is  covered  with  forests  of  chestnuts,  oaks, 
beeches,  and  cork  trees.  The  third  and  highest  zone  in- 
cludes the  rest  of  the  mountain,  and  may  be  called  the 
desert  zone,  since  it  is  a  sterile  region,  covered  with  huge 
blocks  of  lava  and  scoriae,  and  terminating,  in  the  higher 
portions,  in  a  snow-covered  plain,  from  which  the  central 
cone  rises. 

[73] 


74  VOLCANOES  AND  EARTHQUAKES 

Etna  is  continually  sending  up  columns  of  steam  and 
sulphur  vapor.  Every  now  and  then  it  starts  in  eruption, 
throwing  out  large  quantities  of  lava  either  from  the  crater 
on  its  summit,  or  from  some  of  the  200  smaller  cones  or 
craters  that  occupy  portions  of  its  slopes.  On  account, 
probably,  of  its  height  the  eruptions  are  most  frequently 
on  the  sides.  Etna  affords  a  magnificent  example  of  a 
huge  volcanic  pile  of  the  Vesuvian  type,  which  has  been 
slowly  built  up  by  the  gradual  accumulation  of  materials 
that  have  escaped  from  its  craters. 

One  of  the  most  interesting  features  of  the  higher 
regions  of  Etna  is  an  immense  chasm  rent  in  a  side  of 
the  cone  near  the  summit,  and  known  as  the  Val  del 
Bove.  This  chasm  forms  a  vast  amphitheater. 

The  great  force  that  removed  such  an  immense  mass 
of  matter  from  the  cone  could  not  have  been  the  eroding 
power  of  water,  since  the  materials  of  the  cone  are  too 
porous  to  permit  streams  of  any  size  to  rush  down  the 
slopes.  The  force  is  most  probably  to  be  found  in  some 
explosive  eruption  of  the  mountain,  when  a  portion  of 
the  crater  was  suddenly  blown  off,  just  as  was  done  in 
Vesuvius  when  a  large  part  of  the  old  crater  of  Somma 
was  blown  away.  What  is  especially  interesting  about 
the  Val  del  Bove  is  the  opportunity  it  affords  for  studying 
the  interior  structure  of  the  mountain,  for  it  practically 
enables  one  to  enter  to  almost  the  heart  of  this  great 
volcano. 

The  Val  del  Bove  has  the  shape  of  a  great  pit  five  miles 
in  diameter.  It  has  almost  vertical  walls,  the  height  of 
which  varies  with  their  position.  Those  which  reach 
highest  up  the  mountain  vary  from  3,000  to  4,000  feet 
in  height. 

Like  Vesuvius,  Etna  has  been  split  or  fissured  into  great 
crevices  that  have  been  filled  with  lava  during  the  many 


MEDITERRANEAN  VOLCANOES  75 

eruptions  of  its  central  crater.  On  hardening,  these  lava 
streams  form  what  are  known  as  dikes.  As  the  sides  of 
the  mountain  are  worn  away  by  erosion,  the  dikes,  being 
harder  than  the  rest  of  the  cone,  project  from  its  sides 
like  huge  walls.  An  excellent  opportunity  for  seeing  them 
is  afforded  in  the  walls  of  the  Val  del  Bove. 

Sir  Charles  Lyell,  the  English  geologist,  who  has  care- 
fully studied  Mt.  Etna,  asserts  that  this  mountain  began 
to  be  formed  during  a  geological  period  known  as  the 
Tertiary  Age,  through  a  crater  that  opened  on  the  floor 
of  the  Mediterranean  Sea.  The  material  thus  thrown  out, 
collected  around  the  crater  and  produced  a  mountainous 
pile  that  gradually  emerged  above  the  level  of  the  sea, 
and  on  fresh  materials  continuing  to  be  thrown  out,  at 
length  reached  its  present  height.  It  would  appear  that 
at  some  former  time  in  its  history,  there  were  two  vents 
near  the  top  of  the  mountain,  the  second  crater  being 
formed  immediately  under  the  Val  del  Bove.  Soon,  how- 
ever, the  second  and  lower  crater  was  closed,  the  upper 
one  alone  remaining  active.  The  mountain,  therefore, 
continued  to  be  slowly  raised  in  the  air  by  the  materials 
brought  out  through  this  opening.  Then  came  the  great 
explosive  eruption  during  which  the  side  of  the  mountain 
was  blown  off  to  form  the  great  chasm  of  the  Val  del 
Bove. 

Because  of  its  almost  constant  activity,  Mt.  Etna  must 
have  been  well  known  to  the  ancients,  who  described  some 
of  its  most  violent  eruptions.  The  following  brief  notes 
concerning  these  eruptions  have  been  taken  from  Lyell. 

According  to  Diodorus  Siculus,  an  eruption  that  oc- 
curred before  the  Trojan  war,  caused  the  people  living 
in  districts  near  the  mountain  to  seek  new  homes.  Thu- 
cididies,  the  Greek  historian,  states  that  in  the  sixth  year 
of  the  Peloponnesian  war,  which  would  be  about  the  spring 


76  VOLCANOES  AND  EARTHQUAKES 

of  425  B.  c.,  a  lava  stream  caused  great  destruction  in  the 
neighborhood  of  Campania,  this  being  the  third  eruption 
that  had  occurred  in  Sicily  since  it  had  been  settled  by 
the  Greeks. 

Seneca,  during  the  first  century  of  the  Christian  Era, 
calls  the  attention  of  Lucullus  to  the  fact  that  during  his 
time  Mt.  Ena  had  lost  so  much  of  its  height  that  it  could 
no  longer  be  seen  by  boatmen  from  points  at  which  it 
had  before  been  readily  visible. 

But  passing  by  these  very  early  eruptions  of  Etna  we 
come  to  the  great  eruption  of  1669.  This  eruption  was 
preceded  by  an  earthquake  that  destroyed  many  houses 
in  a  town  situated  in  the  lower  part  of  the  forest  zone, 
about  twenty-five  miles  below  the  summit  of  the  moun- 
tain, and  ten  miles  from  the  sea  at  Catania.  During  this 
eruption  two  deep  fissures  were  opened  near  Catania. 
From  these  such  quantities  of  sand  and  scoriae  were  thrown 
out,  that,  in  the  course  of  three  or  four  months,  a  double 
cone  was  formed  450  feet  high,  which  is  now  known  as 
Monte  Rosso.  But  what  was  most  curious  was  the  sudden 
opening,  with  a  loud  crash,  of  a  fissure  six  feet  broad 
reaching  down  to  unknown  depths  that  extended  in  a 
somewhat  crooked  course  to  within  a  mile  of  the  summit 
of  Etna.  This  great  fissure  was  twelve  miles  in  length 
and  emitted  a  most  vivid  light.  Five  other  parallel 
fissures  of  considerable  length  opened,  one  after  another, 
throwing  out  vapor,  and  emitting  bellowing  sounds  which 
were  heard  at  a  distance  of  forty  miles.  These  fissures 
were  afterwards  filled  with  molten  rock,  and  in  this  man- 
ner were  formed  the  long  dikes  of  porphyry  and  other 
rocks  that  are  seen  to  be  passing  through  some  of  the  older 
lavas  of  Mt.  Etna. 

The  great  lava  streams  which  flowed  down  the  side  of 
the  mountain  during  this  eruption,  destroyed  fourteen 


MEDITERRANEAN  VOLCANOES 


77 


78      VOLCANOES  AND  EARTHQUAKES 

towns  and  villages,  and  at  length  reached  Catania.  A 
great  wall  had  been  raised  around  this  city  to  prevent  the 
lava  from  entering  it.  The  molten  rock,  however,  accu- 
mulated, until  it  rose  to  the  top  of  the  wall,  which  was 
sixty  feet  high,  and  then  pouring  over  it  in  a  fiery  cascade, 
overwhelmed  part  of  the  city.  It  is  said  that  during  the 
first  part  of  its  journey,  the  lava  streams  moved  over 
thirteen  miles  in  twenty  days,  or  at  the  rate  of  162  feet 
an  hour.  Beyond  this,  after  the  lava  had  thickened  by 
cooling,  it  had  a  velocity  of  only  twenty-two  feet  per  hour. 

Fig.  14  represents  a  plan  of  Mt.  Etna  reduced  from 
a  map  by  the  Italian  Government.  During  the  erup- 
tion of  1865,  a  rent  was  made  in  the  mountain  extend- 
ing from  Mount  Frumento  (B  in  the  preceding  map)  for 
one  and  one-half  miles,  and  six  cones  from  300  to  350  feet 
in  height  were  formed  along  the  fissure. 

During  the  eruption  of  1874,  great  fissures  three  miles 
in  length  were  formed  in  the  mountain. 

There  exists  on  the  slopes  of  Mt.  Etna  vast  subterranean 
grottoes  formed  by  the  sudden  conversion  into  steam  of 
great  quantities  of  water  that  were  overwhelmed  by  the 
molten  mass.  These  immense  volumes  of  steam  produced 
enormous  bubbles  in  the  molten  lava.  When  the  lava 
hardened  irregular  grottoes  were  left.  Lyell  describes  one 
of  these  as  follows: 

"Near  Nicolosi,  not  far  from  Monte  Rosso,  one  of  these 
great  openings  may  be  seen,  called  the  Fossa  della  Pa- 
lomba,  625  feet  in  circumference  at  its  mouth  and  seventy- 
eight  deep.  After  reaching  the  bottom  of  this,  we  enter 
another  dark  cavity,  and  then  others  in  succession,  some- 
times descending  precipices  by  means  of  ladders.  At 
length,  the  vaults  terminate  in  a  great  gallery  ninety  feet 
long,  and  from  fifteen  to  fifty  broad,  beyond  which  there 
is  still  a  passage,  never  yet  explored,  so  that  the  extent  of 


MEDITERRANEAN  VOLCANOES  79 


80  VOLCANOES  AND  EARTHQUAKES 

these  caverns  remains  unknown.  The  walls  and  roofs  of 
these  great  vaults  are  composed  of  rough  bristling  scoriae 
of  the  most  fantastic  forms." 

Besides  the  eruptions  mentioned  there  have  been  many 
others,  such  as  those  of  1811,  1819,  and  1852.  The  last  of 
these  was  greater  than  any  eruption  except  that  of  1669. 
It  began  in  August,  1852,  and  continued  until  May,  1853, 
and  was  remarkable  for  the  immense  quantity  of  lava 
thrown  out. 

We  come  now  to  the  volcano  of  Stromboli.  Stromboli, 
one  of  the  Lipari  islands,  is  situated  about  sixteen  miles 
west  of  the  Straits  of  Messina.  Its  general  appearance  is 
shown  in  Fig.  15.  The  form  of  the  mountain  is  that  of 
an  irregular  four-sided  pyramid,  which  rises  about  3,090 
feet  above  the  level  of  the  Mediterranean,  and  stands  on 
the  bottom  of  the  sea  in  water  about  3,000  feet  deep. 

If  you  carefully  examine  the  appearance  of  Stromboli, 
as  shown  in  the  preceding  figure,  you  will  notice  that  the 
flat  cloud  which  hangs  over  the  island  is  made  up  of  a 
number  of  globular  masses  of  vapor,  formed  during  the 
peculiar  action  of  the  volcano. 

When  examined  by  night  Stromboli  presents  a  stjll 
more  curious  appearance.  Since  the  mountain  stands 
alone,  its  height  permits  it  to  be  seen  readily  at  sea  for 
distances  of  at  least  a  hundred  miles.  At  night  a  curious 
glow  of  red  light  may  be  seen  on  the  lower  surfaces  of  the 
cloud.  This  light  is  not  continuous,  but  increases  in  in- 
tensity from  a  faint  glow  to  a  fairly  bright  red  light,  then 
gradually  decreases,  and  finally  dies  away  completely. 
After  awhile  the  light  again  appears,  again  gradually 
decreases,  and  disappears,  and  this  continues  until  the 
rising  sun  prevents  the  red  glow  from  being  any  longer 
visible.  Stromboli,  therefore,  acts  not  unlike  the  flashing 
lighthouses  so  common  on  the  sea  coasts  of  all  parts  of 


MEDITERRANEAN  VOLCANOES  81 

the  world.  Indeed,  it  is  actually  used  by  sailors  in  the 
Mediterranean  for  the  purpose  of  showing  them  their 
direction.  For  this  reason  Stromboli  is  commonly  called 
"The  Lighthouse  of  the  Mediterranean." 

As  Judd  remarks,  from  whom  much  of  the  information 
concerning  some  of  the  volcanic  districts  of  the  Mediter- 
ranean has  been  obtained,  the  flashing  light  of  Strom- 
boli differs  from  that  of  the  ordinary  flashing  light  in  two 
important  respects;  viz.,  in  the  intervals  that  elapse  be- 
tween the  successive  flashes,  and  in  the  intensity  of  the 
light  emitted.  As  you  know,  it  is  necessary  that  the  dif- 
ferent lighthouses  placed  near  one  another  on  a  coast  must 
have  their  lights  of  such  a  nature  that  they  can  be  readily 
distinguished.  In  order  to  do  this,  the  flashing  light  has 
been  devised.  In  flashing  lighthouses,  the  lights  only  ap- 
pear at  intervals,  one  lighthouse  being  distinguished  from 
another  in  its  neighborhood  by  the  intervals  between  suc- 
cessive flashes,  or,  sometimes,  indeed,  by  the  color  of 
some  of  the  flashes.  Now,  in  the  case  of  Stromboli,  the 
intervals  between  the  successive  glowings  of  the  red  lights 
are  very  irregular,  varying  between  one  and  twenty 
flashes  per  second.  Moreover,  the  intensity  of  the  light 
also  varies  greatly  from  time  to  time. 

You  naturally  inquire  as  to  the  cause  of  these  flashes 
of  light  that  are  emitted  by  Stromboli.  If,  as  Judd  sug- 
gests, you  should  climb  to  the  summit  of  the  mountain, 
during  the  daytime,  and  look  down  the  inside  of  the  crater, 
you  could  see  its  black  slag  bottom  crossed  by  many  cracks 
and  fissures.  From  most  of  the  smaller  fissures  the  vapor 
of  water  is  quietly  escaping.  This  vapor  rises  in  the  air 
in  which  it  soon  disappears.  There  are,  however,  larger 
cracks  on  the  bottom  of  the  crater  from  which,  at  more  or 
less  regular  intervals,  masses  of  steam  are  emitted  with 
loud  snorting  puffs  not  unlike  those  produced  by  a  loco- 
F 


82  VOLCANOES  AND  EARTHQUAKES 

motive.  From  some  of  the  openings  molten  matter  is 
seen  slowly  oozing  out,  collecting  in  parts  of  the  crater 
and  moving  up  and  down  in  a  heaving  motion.  Every  now 
and  then  a  bubble  is  formed  on  the  surface  of  this  liquid. 
The  bubble  swells  to  a  gigantic  size,  and  suddenly  bursts. 
The  steam  it  contained  escapes,  carrying  fragments  of 
scum  which  are  thrown  high  into  the  air.  The  masses  of 
steam,  formed  below  the  surface  of  the  sticky,  boiling, 
lava,  in  endeavoring  to  escape,  force  their  way  through 
the  mass,  blow  huge  bubbles,  which,  on  bursting,  produce 
the  roaring  sounds  that  are  heard,  and  throwing  great 
columns  of  vapor  in  the  air,  produce  the  rounded  masses 
of  clouds  you  can  see  floating  high  up  in  the  air  over 
the  mountain.  At  the  same  time  the  scum  is  partially 
removed  from  the  red  hot  surface,  its  light  illumines  the 
lower  surface  of  the  overhanging  cloud,  which  flings  it 
back  again  to  the  earth.  With  the  bursting  of  each  bub- 
ble, and  the  clearing  of  the  scum  from  the  surface  of  the 
red  hot  mass,  the  light  begins,  increases  in  intensity,  and 
then  as  the  scum  again  begins  to  collect  on  the  surface, 
decreases,  and  finally  disappears,  and  not  until  the  burst- 
ing of  the  next  bubble  is  it  again  visible. 

But  let  us  make  a  study  of  some  of  the  peculiarities  of 
Vulcano,  another  of  the  Lipari  islands,  which  lies  north 
of  Sicily. 

Vulcano  affords  a  curious  example  of  a  volcano  that 
has  been  harnessed  by  man,  or  made  to  do  work  for  him. 
All  volcanoes  bring  from  inside  of  the  earth  different 
kinds  of  chemical  substances,  in  the  form  of  vapors, 
gases,  or  molten  materials.  Now,  these  materials  acting 
on  one  another,  produce  chemical  substances  some  of 
which,  such  as  sal  ammoniac,  sulphur,  and  boracic  acid, 
possess  commercial  value.  This  is  especially  true  in  the 
case  of  Vulcano,  and  since  the  eruptions  are  not  generally 


MEDITERRANEAN  VOLCANOES  83 

violent,  a  chemical  works  has  actually  been  erected  by  a 
Scotch  firm  on  the  side  of  the  mountain,  where  the  mate- 
rials are  collected  from  the  crevices. 

This  effort  to  harness  a  volcano  was  for  a  time  so  suc- 
cessful that  the  same  people  contemplated  the  building 
of  great  leaden  chambers  over  the  principal  fissure  at  the 
bottom  of  the  crater,  so  that  the  large  volumes  of  ejected 
vapors  might  be  condensed  and  collected.  But  Vulcano, 
like  all  other  volcanoes,  could  not  be  relied  on  continually 
to  keep  the  peace.  One  day  it  suddenly  burst  forth  more 
fiercely  than  usual,  so  that  the  workmen  were  compelled 
to  abandon  the  factory  and  fly  down  the  mountain  for 
their  lives,  but  not,  however,  before  some  of  them  were 
severely  injured  by  the  explosions. 

Vulcano  is  an  instance  of  a  volcano  in  an  almost  ex- 
hausted or  dormant  condition.  It  has  had,  however, 
many  eruptions  during  the  past  few  centuries,  some  of 
which  have  been  very  violent,  for  example,  that  of  1783, 
and  that  of  1786. 

There  still  remains  to  be  considered  the  volcanic  region 
of  the  Santorin  group  of  the  Grecian  Archipelago.  The 
island  of  Santorin  or  Thera,  is  the  southernmost  of  the 
Cyclades.  It  is  an  exceedingly  curious  island,  being  a  sub- 
merged volcano,  with  most  of  the  top  of  the  crater  re- 
maining above  the  waters,  so  that  the  entire  island  has 
the  shape  of  an  irregular  circle  or  crescent  broken  at 
several  points.  Its  formation  is,  probably,  due  to  the 
gradual  sinking  of  a  volcanic  mountain  until  its  crater 
has  been  almost  completely  submerged,  only  the  higher 
parts  of  the  edges  of  the  crater  being  left  above  the  surface 
of  the  waters.  Suppose,  for  example,  a  mountain  like 
Vesuvius  at  the  time  the  crater  Somma  existed,  was  sunk 
below  the  level  of  the  Mediterranean  until  only  the  high- 
est parts  of  the  crater  remained  above  the  waters.  If, 


84  VOLCANOES  AND  EARTHQUAKES 

now,  one  or  more  volcanic  eruptions  occurred,  producing 
craters  or  volcanic  islands  inside  the  submerged  rim,  you 
would  have  a  condition  of  affairs  seen  in  the  island  of 
Santorin. 


CHAPTER  VII 

ORIZABA,  POPOCATEPETL,  IXTACCIHTJATL,  AND  OTHER  VOL- 
CANOES OF  MEXICO 

While  some  of  the  volcanoes  of  Mexico  are  still  in  an 
active  condition,  most  of  them  are  either  only  slightly 
active  or  are  dormant  or  extinct.  Humboldt,  the  cele- 
brated traveller  and  geographer,  states  that  there  are  only 
four  active  volcanic  mountains  in  Mexico;  namely,  Popo- 
catepetl, Tuxtula,  Colima,  and  Jorullo.  But  there  are 
many  others,  among  which  may  be  mentioned  Orizaba, 
Ixtaccihuatl,  Xinantecatl,  Tuxtula,  Cofre  de  Perote,  and 
Colima. 

Of  course,  you  can  understand  that,  since  extinct  vol- 
canoes may  at  any  time  become  active,  in  parts  of  the 
world  where  communication  with  the  interior  is  not  good, 
many  volcanic  mountains  that  have  been  regarded  as 
extinct  may  have  broken  out  temporarily,  during  his- 
torical times,  without  their  eruptions  having  been  re- 
corded. 

It  was  at  one  time  thought  that  Popocatepetl  was  the 
highest  mountain  in  North  America.  More  recent  meas- 
urements, however,  have  shown  that  there  are  at  least 
three  other  mountains  in  this  part  of  the  world,  that  are 
much  higher.  One  of  these  is  the  active  volcano  of 
Orizaba  that  we  will  now  briefly  describe. 

Orizaba  is  situated  in  the  north  central  part  of  Mexico, 
about  seventy-five  miles  west  of  Vera  Cruz.  Its  ancient 
Aztec  name  was  Cittaltepetl,  or  Star  Mountain.  The 
[85] 


VOLCANOES  AND  EARTHQUAKES 


MEXICAN  VOLCANOES  87 

height  of  the  mountain  is  18,200  feet.  Like  all  high 
tropical  mountains  whose  summits  are  snow-clad,  one 
would  pass  through  the  same  changes  in  climate,  in  going 
from  its  base  to  its  summit,  as  in  going  along  the  earth's 
surface  from  the  equator  to  the  poles.  Near  the  base  of 
the  mountain  will  be  found  a  tropical  climate,  above  that 
a  temperate  climate,  while  in  still  higher  regions,  the 
climate  of  the  Arctic  region. 

According  to  Russell,  from  whose  work  on  the  volcanoes 
of  North  America  much  of  the  information  concerning 
the  volcanoes  of  Mexico  and  Central  America  has  been 
condensed,  Orizaba  has  three  craters  on  its  summit.  The 
last  recorded  eruption  took  place  about  the  middle  of  the 
Eighteenth  Century.  The  mountain  is  now  in  a  dormant 
or  extinct  condition,  as  may  be  seen  from  the  fact  that  its 
three  craters  are  for  the  greater  part  filled  with  snow. 

Orizaba,  like  Etna,  and  many  other  volcanoes,  has  deep 
fissures  extending  through  its  sides.  Through  these,  lava 
streams  have  flowed  during  times  when  it  was  active. 
There  are  also  found  on  the  slopes  of  this  mountain  many 
cones  of  a  type  known  as  parasitic  cones.  These  cones  are 
not  caused  by  materials  that  have  been  brought  to  the  sur- 
face during  an  eruption,  but  have  been  formed  by  the 
steam  passing  through  lava  streams  that  have  come  out 
of  the  crater  during  other  eruptions. 

Popocatepetl,  or,  as  the  word  means,  The  Smoking  Moun- 
tain, is  the  second  highest  mountain  in  Mexico.  Accord- 
ing to  recent  measurements  made  by  the  Mexican  Govern- 
ment, its  height  is  17,876  feet.  Popocatepetl  is  situated 
on  the  edge  of  the  great  plateau  of  Mexico,  forty  miles 
southeast  of  the  City  of  Mexico.  It  is  a  conical  mountain, 
and  is  a  magnificent  object  when  seen  from  the  City  of 
Mexico,  rising,  as  it  does,  fully  10,000  feet  from  the  ele- 
vation of  the  city,  while  on  the  east  it  towers  for  nearly 


88  VOLCANOES  AND  EARTHQUAKES 

18,000  feet  above  the  level  of  the  sea.  This  splendid 
mountain  is  poetically  described  by  Russell: 

"Seen  from  the  basal  plains,  it  sweeps  up  in  one  grand 
curve  to  nearly  its  full  height, — a  collossus  of  three  and  a 
quarter  miles  in  elevation,  white  with  everlasting  frost  on 
its  summit,  and  bathed  in  the  green  of  palms,  bananas, 
oranges,  and  mangoes,  at  its  base.  Evergreen  oaks  and 
pines  encircle  its  middle  height,  and  above  them,  before 
the  ice  itself  is  reached,  occur  broad  areas  of  loose  sand 
into  which  the  lavas  have  been  changed  by  weathering. 
Soft  wreaths  of  sulphurous  vapor  may  at  times  be  seen 
curling  over  the  crest  of  the  summit  crater, — gentle  re- 
minders that  the  days  of  volcanic  activity  are  not  yet 
necessarily  over." 

Popocatepetl  takes  its  name,  The  Smoking  Mountain 
from  the  fact  that  gases  and  vapor  are  continually  being 
emitted  from  its  summit  crater.  It  has  a  conical  peak 
with  a  depression  or  crater  on  its  summit.  The  bottom 
of  the  crater  is  crossed  by  fissures  from  which  small  quan- 
tities of  steam  escape,  not,  however,  sufficient  to  melt  all 
the  snow  which  covers  the  slopes  of  the  mountain  to  a 
depth  of  from  eight  to  ten  feet.  A  small  lake  of  hot  water 
has  collected  in  the  crater  from  the  water  derived  from 
the  melting  snow.  This  water,  sinking  through  the  porous 
materials  in  the  cone,  is  the  source  of  a  great  number  of 
large  hot  springs  that  occur  around  the  base  of  the  moun- 
tain. 

Reclus  states  that  the  first  to  climb  to  the  top  of  Popo- 
catepetl was  one  of  Cortez'  officers,  1519. 

Another  snow-capped  volcano,  which  rising  from  the 
plain  of  Mexico  is  in  clear  view  of  the  city,  is  Ixtaccihuatl 
(Ets-tak'-se-wat-el),  or  as  the  word  means  in  the  ancient 
Aztec,  The  White  Woman.  This  mountain,  as  measured  by 
Heilprin,  is  16,960  feet  in  height.  Ixtaccihuatl  is  now  in  so 


MEXICAN  VOLCANOES  89 

dormant  a  condition  that  many  who  have  climbed  to  the 
top  assert  that  it  is  not  a  volcano  at  all,  since  they  find 
no  crater  on  its  summit.  Nor  are  there  any  signs  of  vol- 
canic heat,  the  summit  being  snow  clad  during  summer. 
The  conical  form  of  the  mountain,  however,  and  the  fact 
that  the  entire  mountain  is  formed  of  volcanic  rocks,  show 
beyond  doubt  that  it  is  an  extinct  volcano,  whose  crater 
has  most  probably  been  completely  filled  in  by  the  wash- 
ing away  of  its  sides. 

Xinantecatl  is  another  extinct  volcanic  mountain  sit- 
uated about  forty  miles  southwest  of  the  City  of  Mexico. 
It  is  about  16,500  feet  high.  Its  name  means  in  the  an- 
cient Aztec  language,  The  Naked  Lord.  It  is  also  some- 
times known  as  the  Nevado  de  Toluca,  or  The  Snow  of 
Toluca.  On  the  top  of  the  peak  are  two  craters  filled  with 
lakes  of  fresh  water.  Russell  states  that  the  larger  of 
these  lakes  is  about  thirty  feet  in  depth  and  contain  a 
peculiar  species  of  fish. 

Tuxtula  is  another  volcano  of  Mexico,  situated  on  the 
western  coast  of  the  Gulf  of  Mexico,  about  eighty  miles 
southeast  of  Vera  Cruz.  It  was  an  active  volcano  in  1664, 
when  it  threw  out  molten  lava.  It  then  became  dormant 
until  March,  1793,  when  its  long  rest  was  broken  by  one 
of  the  grandest  explosive  eruptions  of  modern  times. 
This  eruption  rivalled  in  energy  the  great  explosive  erup- 
tion which  blew  off  the  summit  of  Coseguina,  in  Central 
America,  in  1835.  As  is  common  in  the  case  of  explosive 
eruptions,  volcanic  dust  and  scoriae  were  blown  high  into 
the  air,  and,  being  carried  by  the  winds,  fell  on  the  roofs 
of  houses  and  on  the  land  at  a  distance  of  150  miles. 

There  have  been  a  number  of  less  violent  eruptions  of 
Tuxtula  since  1835.  Tuxtula  is  a  comparatively  low 
mountain,  being  only  4,960  feet  high,  because  much  of 
the  mountain  was  blown  away  by  the  eruption  of  1793. 


90  VOLCANOES  AND  EARTHQUAKES 

As  Russell  points  out,  it  is  not  safe  to  infer  that  because 
an  eroded  mountain  is  not  lofty  it  cannot  be  young  or 
energetic,  since  the  very  energy  of  some  of  its  eruptions 
may,  as  in  the  case  of  Tuxtula,  blow  away  a  large  part  of 
the  mountain.  A  low  mountain,  with  an  unusually  large 
crater,  generally  means  a  mountain  that  has  been  visited 
by  a  great  explosive  eruption. 

Another  extinct  volcano  known  as  the  Cofre  de  Perote 
is  situated  on  the  eastern  coast  of  Mexico,  east  of  Ixtac- 
cihuatl,  about  thirty  miles  north  of  Orizaba.  It  takes  its 
name  Cofre  de  Perote  which  means  the  Coffin  of  Perote, 
from  its  peculiar  box-like  shape.  It  was  called  in  the 
Aztec  language  "Nauhcampatepetl,"  or  the  Four-Ridged 
Mountain.  Cofre  de  Perote  is  in  a  dormant  or  extinct 
condition. 

We  will  conclude  this  brief  description  of  the  volcanoes 
of  Mexico  with  the  volcano  of  Colima,  a  mountain  about 
5,500  feet  high  situated  on  the  western  coast  of  Mexico. 

Colima  has  been  active  of  recent  years,  eruptions  hav- 
ing occurred  in  1869,  1872,  1873,  and  1885.  During 
these  eruptions  lava  escaped  from  lateral  openings  in 
the  sides  of  the  mountain,  these  openings  being  termed  by 
the  natives  the  Sons  of  Colima. 


CHAPTER  VIII 

COSEGUINA  AND   OTHER  VOLCANOES  OF  CENTRAL  AMERICA 

Central  America  has  a  great  number  of  volcanoes  ex- 
tending along  nearly  all  its  western  coast,  or  on  the 
Pacific  side  of  the  country. 

Central  America  consists  of  a  high  plain  or  table-land 
sloping  gently  towards  the  northeast,  but  terminating 
abruptly  on  the  southwest.  In  the  opinion  of  geologists 
this  table-land  consists  of  the  surface  of  a  huge  tilted 
block  of  the  earth's  crust,  or,  perhaps,  more  probably, 
of  a  series  of  such  blocks,  that  are  limited  on  the  south- 
west by  a  narrow  belt  of  intersecting  fractures.  It  is  in 
these  fractures  that  scores  of  volcanoes  are  situated,  to- 
gether with  active  craters,  solfataras,  and  hot  springs. 
The  volcanoes  are  mainly  of  the  Vesuvian  type.  There 
are  so  many  volcanoes  in  this  part  of  the  world  that  it 
will  be  possible  to  describe  but  a  few  of  them. 

We  will  begin  with  the  volcano  of  Coseguina,  situated 
on  the  Pacific  coast  of  Nicaragua.  Its  appearance  is  that 
of  a  conical  mountain  with  the  top  cut  off,  and  suggests 
that  it  is  most  probably  an  explosive  volcano  which  has 
had  the  top  blown  away  during  some  of  its  great  erup- 
tions. 

Coseguina  is  celebrated  by  reason  of  its  tremendous 
eruption  of  1835.  Before  the  still  more  tremendous  ex- 
plosive eruption  of  Krakatoa  in  1883,  described  in  the 
first  two  chapters  of  this  book,  Coseguina  shared  with 
[91] 


92  VOLCANOES  AND  EARTHQUAKES 

Sombawa,  on  the  island  of  Sumatra,  as  being  the  fore- 
most of  explosive  volcanoes. 

It  had  been  estimated  that  before  its  eruption  of  1835, 
Coseguina  had  a  height  of  perhaps  10,000  feet,  but  so 
much  of  it  was  blown  away  by  this  eruption  that  it  now  is 
a  little  less  than  4,000  feet. 

The  following  description  of  the  great  eruption  of  Cose- 
guina in  1835  has  been  condensed  from  an  account  pre- 
pared by  Squier,  published  in  1850. 

You  will  note  in  reading  this  brief  account  how  closely 
many  of  the  phenomena  resemble  those  that  occurred 
during  the  eruption  of  Krakatoa  in  1833. 

The  eruption  of  Coseguina  was  heralded  on  the  morning 
of  January  20th,  1835,  by  several  loud  explosions  that 
were  heard  for  a  distance  of  some  300  miles  around  the 
crater  of  the  volcano.  Then  followed  an  ink  black  cloud 
formed  directly  over  the  mountain,  which  gradually 
spread  on  all  sides  shutting  off  the  light  of  the  sun,  except 
for  a  sickly  yellowish  light.  Fine  sand  was  thrown  from 
this  cloud,  which  made  it  both  difficult  and  painful  to 
breathe.  For  two  whole  days  the  cloud  continued  to  grow 
denser,  the  explosions  louder  and  more  frequent,  and  the 
rain  of  sand  thicker.  On  the  third  day  the  explosions 
were  strongest  and  the  darkness  greatest. 

The  amount  of  sand  that  fell  from  the  cloud  was  so 
great  that  people  left  their  houses,  fearing  the  roofs  would 
be  crushed  in  by  the  great  weight.  This  sand  fell  in  large 
quantities  over  an  area  more  than  1,500  miles  in  diameter, 
or,  quoting  the  language  of  Squier: 

"The  noise  of  the  explosions  was  heard  nearly  as  far" 
(1,500  miles).  "And  the  Superintendent  of  Belize,  eight 
hundred  miles  distant,  mustered  his  troops,  under  the 
impression  that  there  was  a  naval  action  off  the  harbor. 
All  nature  seemed  overawed;  the  birds  deserted  the  air, 


CENTRAL  AMERICAN  VOLCANOES          93 

and  the  wild  beasts  their  fastnesses,  crouching,  terror- 
stricken  and  harmless,  in  the  dwellings  of  men.  The 
people  for  a  hundred  leagues  grouped,  dumb  with  terror, 
amidst  the  thick  darkness,  bearing  crosses  on  their  shoul- 
ders and  stones  on  their  heads  in  penitential  abasement 
and  dismay.  Many  believed  that  the  day  of  doom  had 
come,  and  crowded  in  the  tottering  churches,  where,  in 
the  pauses  of  the  explosions,  the  voices  of  the  priests  were 
heard  in  solemn  invocation  to  Heaven.  The  brightest 
lights  were  invisible  at  the  distance  of  a  few  feet;  and  to 
heighten  the  terror  of  the  scene,  occasional  lightnings 
traversed  the  darkness,  shedding  a  lurid  glare  over  the 
earth.  This  continued  for  forty-three  hours,  and  then 
gradually  passed  away." 

It  appears  that  the  eruption  of  Cosequina  was  followed 
by  violent  earthquake  shocks  and  other  evidences  of 
volcanic  energy  over  extended  regions.  For  example, 
there  were  fearful  earthquakes  along  the  Andes,  the  worst 
of  which  occurred  on  February  20th,  and  continued  at  the 
rate  of  three  or  four  a  day  up  to  March  6th,  and,  less 
frequently,  to  March  17th.  It  was  during  one  of  these 
earthquakes  that  the  city  of  Concepcion,  Chile,  was  so 
completely  destroyed,  that  but  a  single  house  remained. 

The  same  brilliant  sunsets  and  sunrises  occurred  in 
different  parts  of  the  world  after  the  eruption  of  Cose- 
guina,  due  to  the  presence  of  large  quantities  of  volcanic 
dust  that  followed  the  great  eruption  of  Krakatoa. 

The  cause  of  this  great  explosive  eruption  of  Coseguina 
was  most  probably  the  same  as  that  which  is  believed  to 
have  caused  the  eruption  of  Krakatoa,  namely,  a  large 
volume  of  water  suddenly  gaining  access  to  a  mass  of 
liquid  lava. 

Volcan  del  Fuego  is  another  of  the  many  volcanoes  of 
Central  America,  It  is  situated  as  one  of  a  group  of  vol- 


94  VOLCANOES  AND  EARTHQUAKES 

canoes  on  the  highest  summit  of  the  Isthmus.  This 
volcanic  mountain  has  a  regular  cone  with  regular  slopes 
on  all  sides,  except  on  the  north,  where  a  table-like  pro- 
jection, about  1,000  feet  below  the  summit,  is  all  that 
remains  of  a  vast  cone,  the  summit  of  which  was  blown 
away,  according  to  Russell,  in  prehistoric  times,  just  as 
was  the  crater  of  Somma  on  Vesuvius. 

There  have  been  in  Central  America,  since  the  time  of 
the  Spanish  conquest,  some  fifty  volcanic  eruptions  suffi- 
ciently great  to  have  been  recorded.  Some  idea  of  the 
activity  of  Fuego  during  this  time  may  be  had  from  the 
fact  that  of  all  these  eruptions  some  twenty  were  those 
of  Fuego.  At  the  present  time,  however,  the  volcano 
is  dormant  and  apparently  almost  extinct. 

The  recorded  eruptions  of  Fuego  are  nearly  all  of  the 
explosive  type.  Among  the  most  violent  were  those  that 
occurred  during  1526,  1541,  and  1581.  During  1582,  1585, 
and  1586,  there  were  eruptions  nearly  every  month,  the 
most  terrible  being  near  Christmas  day  in  1586.  Other 
memorable  eruptions  occurred  in  1614,  1623,  1686,  and 
1705,  and  at  other  dates  down  to  August  17th,  1860,  from 
which  date  to  the  present  time  the  volcano  has  been  quiet. 

We  will  conclude  this  brief  description  of  the  volcanoes 
of  Central  America  with  that  of  Volcan  de  Agua,  or,  as  the 
word  means,  The  Water  Volcano.  It  is  situated  in  Guate- 
mala near  the  coast,  and  is  one  of  the  mountains  that 
occupies  the  plateau  on  which  Fuego  is  situated. 

The  Volcan  de  Agua  is  one  of  the  most  remarkable  vol- 
canoes in  Central  America,  standing,  as  it  does,  nearly 
alone,  and  rising  to  an  elevation  of  3,350  metres  (10,988  ft.), 
above  the  level  of  the  sea.  It  has  been  extinct  for  a  long 
time. 

It  has  been  supposed  by  some,  from  its  name,  that  this 
is  a  volcano  that  throws  out  water.  Others  believe  that 


CENTRAL  AMERICAN  VOLCANOES  95 

the  name  comes  from  the  water  produced  by  the  melting 
of  the  snow  that  is  collected  on  the  sides  of  the  mountain. 
Now  there  almost  always  escapes  from  the  craters  of 
volcanoes  during  violent  eruptions  immense  quantities  of 
water  vapor,  which,  condensing,  fall  as  vast  showers  of 
rain  that  often  deluge  the  surrounding  country.  In  snow- 
clad  mountains,  the  escape  of  lava  is  often  attended 
by  floods  caused  by  the  rapid  melting  of  the  snow.  The 
water  volcano  did  not,  however,  take  its  name  from 
either  of  these  facts,  but  rather  because  at  the  time  of  the 
Spanish  invasion,  the  crater  of  the  mountain  was  occupied 
by  a  large  lake,  and  that  during  an  earthquake  in  1541 
the  wall  of  the  crater  was  broken,  when  the  lake  was 
poured  as  an  immense  stream  of  water  down  the  side  of 
the  mountain,  overwhelming  a  village  which  was  situated 
on  this  slope.  That  this  was  the  correct  origin  of  the  same 
may  be  seen  from  the  fact  that  the  crater  at  the  present 
time  still  shows  the  remains  of  its  former  lake  basin,  and 
that  on  the  sides  of  the  broken  rim  an  immense  ravine  can 
be  seen  through  which  the  water  poured  down  on  the 
village  below. 

Daubeny  describes  this  volcano  as  follows: 
"The  Volcan  de  Agua  (Water- Volcano)  is  of  enormous 
height,  being  covered  with  eternal  snow,  in  the  latitude 
of  14°.  Captain  Basil  Hall  estimates  it  at  more  than  14,000 
feet,  but  a  recent  traveller  states  it  at  12,600.  It  has  the 
form  of  a  blunted  cone  clothed  with  perpetual  verdure 
to  its  summit.  The  crater  is  from  forty  to  sixty  yards  in 
depth,  and  about  150  in  diameter, — the  sides  and  bottom 
strewed  with  masses  of  rock,  apparently  showing  the 
effects  of  boiling  water  or  of  fire. 

"By  a  deluge  of  water  from  this  volcano  in  1527,  the 
original  city  of  Guatemala  was  overwhelmed;  and  the  next 
built,  called  the  Old  City,  La  Antiqua,  was  ruined  by  an 


96  VOLCANOES  AND  EARTHQUAKES 

earthquake  in  1773.  The  present  capital  is  situated  at  a 
distance  of  eight  leagues  from  the  mountain." 

Another  volcano  in  this  part  of  the  country  is  described 
by  Daubeny  as  follows: 

"Massaya,  near  the  lake  of  that  name,  was  one  of  the 
most  active  vents  at  the  time  of  the  first  discovery  of  the 
country.  Its  flames  were  visible  twenty-five  miles  off. 
Its  crater  was  only  twenty  or  thirty  paces  in  diameter; 
but  the  melted  lava  'seethed  and  rolled  in  waves  as  high 
as  towers.'  A  story  is  told  of  a  Dominican  who  imagined 
the  fluid  lava  was  melted  gold,  and  descended  into  the 
crater  with  an  iron" ladle  to  carry  some  away;  but  the  ladle, 
it  is  said,  melted,  and  the  monk  escaped  with  difficulty." 


CHAPTER  IX 

THE    VOLCANIC    MOUNTAINS    OF    SOUTH    AMERICA 

The  volcanoes  of  South  America  are  limited  to  the 
Andes  Mountain  System  that  stretches  like  a  huge  wall 
along  the  entire  western  side  of  the  continent.  The  names 
of  the  more  important  of  these  volcanoes  are  marked  on 
the  map  of  South  America,  shown  in  Fig.  17.  As  will  be 
seen,  this  huge  mountain  wall  reaches  from  Patagonia  on 
the  south  to  the  Isthmus  of  Panama  on  the  north.  The 
arrangement  of  the  volcanoes  in  South  America  is  of  the 
linear  type.  The  craters  follow  one  another  in  more  or 
less  straight  lines,  or  are  situated  along  the  lines  of  great 
fissures  that  lie  near  the  ocean.  You  must  not,  however, 
suppose  that  there  is  a  continuous  chain  of  active  volcanic 
mountains  from  the  Isthmus  of  Panama  to  the  southern 
part  of  the  continent,  According  to  Lyell,  from  lat.  2°  N., 
or  from  the  north  of  Quito,  to  lat.  43°  S.  or  south  of 
Chile,  a  total  distance  including  45°  of  latitude,  there  is  a 
succession  of  districts  with  active  and  extinct  volcanoes, 
or  at  least  with  volcanoes  that  have  been  quiet  during 
the  last  three  centuries. 

Lyell  traces  the  volcanoes  of  South  America  as  follows: 
"The  principal  line  of  active  vents  which  have  been 
seen  in  eruption  in  the  Andes  extends  from  lat.  43°28'  S., 
....  to  lat.  30°  S.;  to  these  thirteen  degrees  of  latitude 
succeed  more  than  eight  degrees,  in  which  no  recent  vol- 
canic eruptions  have  been  observed.     We  then  come  to 
the  volcanoes  of  Bolivia  and  Peru,  extending  six  degrees 
G  [97] 


VOLCANOES  AND  EARTHQUAKES 


80'  70°  60'  SO' 

FIG.  17.     SOUTH  AMERICA 


40* 


30* 


SOUTH  AMERICAN  VOLCANOES  99 

from  S.  to  N.,  or  from  lat.  21°  S.  to  lat.  15°  S.  Between 
the  Peruvian  volcanoes  and  those  of  Quito  another  space 
intervenes  of  no  less  than  fourteen  degrees  of  latitude,  in 
which  there  is  said  to  be  but  few  active  volcanoes  as  far 
as  is  yet  known.  The  volcanoes  of  Quito  then  succeed, 
beginning  about  100  geographical  miles  south  of  the  equa- 
tor, and  continuing  for  about  150  miles  north  of  it,  when 
there  occurs  another  undisturbed  region  of  more  than  six 
degrees  of  latitude,  after  which  we  arrive  at  the  volcanoes 
of  Guatemala,  or  Central  America,  north  of  the  Isthmus 
of  Panama." 

Of  course,  you  must  not  understand  that  there  are  no 
extinct  volcanoes  in  these  gaps.  On  the  contrary,  accord- 
ing to  Daubeny,  we  find,  beginning  on  the  north  in  the 
United  States  of  Colombia,  the  lofty  volcano  of  Tolima. 
According  to  Daubeny's  book  published  in  1848,  Tolima 
was  then  constantly  emitting  steam  and  sulphur  gases 
from  its  summit.  Tolima  is  situated  in  the  easternmost 
of  'the  three  mountain  ranges  that  extend  through  this 
section  of  the  country.  It  is,  therefore,  at  a  comparatively 
great  distance  from  the  ocean.  Tolima  was  in  eruption 
in  1595.  It  again  burst  out  in  1826. 

Coming  now  to  Ecuador  we  find  that  this,  the  smallest 
of  the  South  American  Republics,  contains  numerous 
great  volcanic  mountains. 

Some  of  the  principal  volcanic  mountains  are  Chimbo- 
razo,  20,498  feet  above  the  sea;  Antisana,  18,880  feet; 
Cotopaxi,  19,660  feet;  Pichincha  (17,644  feet  in  1848, 
Daubeny),  El  Altar,  16,383  feet. 

These  all  lie  in  South  America  on  the  plateau  of  Quito. 
As  Baron  Alexander  von  Humboldt  has  pointed  out,  the 
volcanic  mountains  of  Quito  are  arranged  in  two  parallel 
chains  that  extend  side  by  side  for  a  distance  of  over  500 
miles  north  into  the  State  of  Colombia,  including  between 


100         VOLCANOES  AND  EARTHQUAKES 

them  the  high  plateaus  of  Quito  and  Lacumbia.  Accord- 
ing to  Whymper,  however,  who  has  recently  studied  this 
part  of  South  America,  there  is  a  succession  of  basins  be- 
tween the  mountains,  but  there  is  no  such  thing  as  a  single 
valley  in  the  interior  of  Ecuador.  The  extinct  volcanoes 
of  Cayamba,  Antisana,  and  Chimborazo  are  the  most 
important.  On  all  three  mountains  there  are  old  lava 
streams  on  their  sides.  Although  no  craters  can  be  seen 
on  their  summits,  yet  it  is  almost  certain  they  once  had  cra- 
ters. There  is  plenty  of  room  on  the  summit  of  Antisana 
for  a  cone  as  great  as  that  of  Cotopaxi.  Whymper  is  of 
the  opinion  that  the  snow  domes  that  form  the  summit 
of  Chimborazo  were  at  one  time  two  of  the  highest 
points  of  the  rim  of  the  old  crater. 

Nearly  due  south  of  Quito  is  the  great  volcanic  cone 
of  El  Altar.  Like  all  the  peaks  of  this  high  plateau,  El 
Altar  rises  to  a  great  height  above  the  sea,  being  at  the 
present  time  16,383  feet  above  the  sea.  This  mountain  has 
an  enormous  crater  that  appears  to  be  dormant  or  ex- 
tinct, and  is  covered  with  snow.  According  to  the  tradi- 
tions of  Indians,  El  Altar,  or,  as  they  call  it,  Capac  Urcu 
or  The  Chief,  was  the  highest  mountain  near  the  equator, 
being  much  higher  than  Chimborazo.  But  during  a  pro- 
digious eruption  that  occurred  before  the  discovery  of 
America,  and  continued  uninterruptedly  for  eight  years, 
the  height  of  the  mountain  was  considerably  reduced. 
According  to  Boussingault,  the  fragments  of  the  cone  of 
this  celebrated  mountain  are  now  spread  for  great  dis- 
tances around  the  mountain  on  the  surrounding  lowlands. 

Pichincha  in  Ecuador,  an  extinct  volcano,  is  situated 
almost  immediately  on  the  equator.  It  has  a  height  as 
measured  by  Whymper  by  the  barometer,  of  15,918  feet 
above  the  Pacific.  The  summit  is  covered  by  blocks  of 
pumice.  Several  species  of  lichens  are  found  at  this 


SOUTH  AMERICAN  VOLCANOES  101 

elevation.  According  to  Daubeny,  Pichincha  was  ex- 
tinct prior  to  1539,  when  it  became  active.  There  were 
also  eruptions  in  1577,  1587,  and  1668.  It  was  also  in 
activity  during  1831. 

Cayamba,  another  volcanic  mountain  of  Ecuador,  lies 
to  the  east  of  Pichincha,  a  short  distance  north  of  the 
equator.  Its  height  is  19,186  feet.  It  is  nearly  extinct. 

Cotopaxi,  19,680  feet,  is  another  volcanic  mountain  of 
the  high  plateau  of  Quito.  Cotopaxi  is  still  active.  Its 
slopes  are  covered  with  snow  down  to  a  height  of  about 
14,800  feet.  Between  the  lower  edge  of  this  snow  line  and 
the  lower  slopes  of  the  mountain,  there  lies  a  zone  of  naked 
rock. 

According  to  Whymper,  the  eruption  of  Cotopaxi,  in 
1877,  was  preceded  by  an  unusual  degree  of  activity  in  the 
earlier  parts  of  the  year.  This,  however,  did  not  cause  any 
alarm  until  June  25th,  1877,  when,  shortly  after  midday, 
an  eruption,  attended  by  tremendous  subterranean  roars, 
began,  and  an  immense  black  column  shot  up  into  the  air 
for  about  twice  the  height  of  the  cone.  This  eruption  was 
clearly  visible  at  Quito,  for  the  wind  blew  the  ashes  to- 
wards the  Pacific.  At  this  time  the  summit  had  not 
changed  its  appearance,  but  towards  6:30  A.  M.,  on  the 
next  day,  another  enormous  column  of  ashes  rose  from 
the  crater.  The  ashes  and  cinders  were  first  carried  due 
north  by  the  winds,  and  then,  spreading  out  in  all  direc- 
tions, were  subsequently  distributed  through  the  air  all 
over  the  country.  At  Quito,  as  early  as  8  A.  M.,  the  sky 
assumed  the  appearance  it  generally  has  at  twilight,  and 
the  darkness  increased  until  midday,  when  it  became  as 
dark  as  at  midnight.  Indeed,  it  was  so  dark  that  one  could 
not  see  his  hand  before  his  face. 

During  this  eruption,  as  is  very  common  in  the  eruptions 
of  the  snow-clad  mountains  of  South  America,  a  flood  of 


102          VOLCANOES  AND  EARTHQUAKES 

water,  due  to  the  rapid  melting  of  the  snow  and  ice  on  the 
summit,  rushed  down  the  mountain  slopes  at  10  o'clock 
A.  M.,  on  the  26th  of  the  month,  almost  immediately  after 
the  appearance  of  a  stream  of  lava  that  began  to  flow  down 
the  mountain.  In  a  few  moments  the  mountain  was 
completely  shut  off  from  view  by  immense  columns  of 
steam  and  smoke.  At  first,  a  low,  moaning  sound  was 
heard,  which  rapidly  increased  to  a  roar,  when  a  deluge 
of  mud,  mingled  with  huge  blocks  of  ice  and  stones,  swept 
down  the  mountain,  leaving  a  desert  in  its  path.  It  is 
estimated  that  at  some  places  this  stream  moved  with  a 
velocity  of  fifty  miles  per  hour. 

The  general  appearance  of  Cotopaxi  is  shown  in  the 
accompanying  reproduction  from  the  painting  by  Frede- 
rick E.  Church  in  the  Lenox  Library,  New  York. 

According  to  Whymper,  who  made  an  ascent  of  Coto- 
paxi in  1880,  the  crater  on  the  summit  has  the  form  of  an 
immense  amphitheatre,  2,300  feet  across  from  north  to 
south,  and  1,650  feet  from  east  to  west.  Its  crest  is  irregu- 
lar and  notched.  The  crater  is  surrounded  by  perpendicu- 
lar cliffs.  The  western  side  of  the  volcano  is  irregular. 
Barometric  measurements  gave  the  height  of  this  volcano 
at  19,498  feet.  Its  height  as  taken  by  La  Condamine, 
during  the  early  parts  of  the  last  century,  was  19,605  feet, 
so  that,  according  to  Whymper,  assuming  as  would  seem 
probable,  that  this  difference  in  height  has  not  all  been  due 
to  errors  in  measurements,  the  volcano  has  grown  or 
increased  in  height  during  the  last  century  and  a  half. 

Chimborazo,  20,498  feet,  is  another  lofty  mountain 
on  the  plateau  of  Quito.  This  volcano  is  situated  in  lat. 
1°  30'  S.,  and  is  not  at  the  present  time  in  an  active  condi- 
tion. It  is,  however,  formed  entirely  of  volcanic  material. 
Its  upper  portions  are  covered  with  a  layer  of  snow  to  a 
level  of  some  2,600  feet  below  the  summit. 


SOUTH  AMERICAN  VOLCANOES  103 

Chimborazo  has  an  enormous  volcanic  summit,  which, 
when  seen  from  the  Pacific,  when  the  air  is  especially 
clear  after  the  long  rains  of  winter,  is  a  most  splendid 
sight.  Whymper,  who  ascended  the  mountain,  says: 

"When  the  transparency  of  the  air  is  increased  and  its 
enormous  circular  summit  is  seen  projected  upon  the  deep 
azure  of  blue  of  the  Equatorial  sky,  it  represents  a  mag- 
nificent sight.  The  great  rarity  of  the  air  through  which 
the  top  of  the  Andes  is  seen  adds  much  to  the  splendor." 

Whymper  says,  that  as  far  as  records  are  concerned, 
there  have  been  no  eruptions  of  Chimborazo,  which  has 
apparently  been  an  extinct  volcano  for  many  years.  Its 
crater  has  been  completely  buried  by  a  thick  cap  of  ice  on 
its  summit,  while  what  lava  streams  exist  on  the  moun- 
tain are  either  covered  by  large  glaciers,  or  have  been 
removed  by  erosion,  or  hidden  by  vegetation. 

Chimborazo  possesses  less  of  the  conical  outline  than 
Cotopaxi.  There  are  steep  cliffs  towards  the  summit  that 
have  been  named  by  Whymper  "the  northern  and  south- 
ern walls."  They  seem  to  him  to  have  been  formed  by 
the  violent  upheavals  of  the  explosive  eruptions  that  have 
blown  away  portions  of  the  cone. 

There  are  other  volcanoes  in  this  district,  but  the  above 
are  all  we  have  space  for  describing. 

According  to  Lyell,  the  volcano  of  Rancagua,  in  Chile, 
lat.  34°  15'  S.,  is  continually  throwing  up  ashes  and 
vapors  like  Stromboli.  Indeed,  a  year  seldom  passes  in 
Chile  without  some  earthquake  shocks.  Of  these  shocks 
those  which  came  from  the  side  nearest  the  sea  are  most 
violent.  The  town  of  Copiapo  was  laid  waste  by  these 
shocks  during  the  years  1773,  1796,  and  1819,  in  both 
instances  after  intervals  of  twenty-three  years. 

Since  the  volcanic  mountains  of  South  America  are 
snow-covered  the  occurrences  of  volcanic  eruptions  are 


104         VOLCANOES  AND  EARTHQUAKES 

apt  to  be  attended  by  great  floods  caused  by  the  rapid 
melting  of  the  snow,  as  well  as  sometimes  by  the  breaking 
of  huge  subterranean  cavities  that  are  filled  with  water. 

According  to  Lyell,  the  volcanoes  of  Peru  rise  from  a 
plateau  from  17,000  to  20,000  feet  above  the  sea.  One 
of  the  principal  volcanoes  of  Peru  is  Arequipa,  whose 
summit  is  18,877  feet  above  the  level  of  the  sea.  The 
mountain  takes  its  name  from  the  city  of  Arequipa, 
which  is  situated  not  far  from  its  base.  It  is  an  active 
volcano.  Another  volcano,  Viejo,  is  found  in  lat.  16°  55'  S. 

According  to  Lyell,  there  are  active  vents  extending 
through  Chile  to  the  island  of  Chiloe  to  lat.  30°  N. 

Aconcagua,  west  of  Valparaiso,  in  lat.  32°  39'  S.,  23,000 
feet  in  height,  the  highest  mountain  in  South  America,  is 
still  in  an  active  condition.  According  to  Scrope,  when 
the  city  of  Mendoza  was  destroyed  by  an  earthquake, 
that  killed  10,000  people,  in  March,  1861,  it  is  probable 
that  Aconcagua  was  in  eruption. 

There  are  many  other  active  volcanoes  in  Chile,  extend- 
ing as  far  south  as  the  volcanoes  of  Patagonia,  north  of 
the  Straits  of  Magellan  as  well  as  others  of  Tierra  del 
Fuego. 


CHAPTER  X 

VOLCANOES  OF  THE  UNITED  STATES 

For  some  readers  this  may  be  a  surprising  chapter 
heading,  for  it  is  a  general  impression  that  there  are  no 
volcanoes  in  the  United  States.  It  is  true  that  practically 
all  of  the  volcanoes  of  this  country  are  dormant  or  ex- 
tinct. They  have,  however,  at  one  time  been  exceedingly 
active,  and,  if  reports  are  correct,  some  of  them  were 
active  during  comparatively  recent  times. 

Nearly  all  of  the  volcanoes  of  the  United  States  lie  west 
of  the  meridian  of  Denver.  These  volcanoes  belong  to 
two  distinct  types,  either  the  Vesuvian  type  with  built 
up  cones,  or  the  plateau  or  fissure  type  already  referred  to. 

The  following  brief  description  of  the  volcanoes  of  the 
United  States  has  been  collated,  for  the  greater  part,  from 
Wallace's  excellent  book  on  the  volcanoes  of  North 
America. 

Crossing  the  United  States  on  the  Southern  Pacific 
Railroad  one's  attention  is  caught,  in  Arizona,  by  a  mag- 
nificent group  of  mountains  known  as  the  San  Francisco 
Mountains.  The  highest  peak  of  these  mountains  reaches 
12,562  feet  above  the  level  of  the  sea,  and  5,700  feet  above 
the  surface  of  the  plateau  on  which  the  mountains  stand. 

According  to  G.  K.  Gilbert,  the  San  Francisco  Moun- 
tain group  is  formed  of  a  variety  of  lava  known  as  tra- 
chyte, that  is  of  comparatively  recent  ejection,  possibly  of 
a  geological  age  called  the  Tertiary.  The  lava  forming 
the  mountains  escaped  through  a  number  of  crater  cones, 
[105] 


106 


VOLCANOES  AND  EARTHQUAKES 


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UNITED  STATES  VOLCANOES  107 

some  of  which  can  still  be  seen  in  the  neighborhood. 
Some  of  these  craters  are  now  in  almost  as  perfect  a  con- 
dition as  the  day  they  were  formed.  Indeed,  to  one  look- 
ing at  them  from  a  neighboring  elevation,  they  appear  so 
fresh,  and  so  little  affected  by  the  climate,  that  one  might 
almost  believe  that  the  lava  had  just  flowed  out  of  the 
craters,  and  has  not  yet  hardened.  Nevertheless,  geolo- 
gists are  sure  they  have  been  formed  long  before  man 
appeared  on  the  earth.  In  one  of  these  craters  a  lake  of 
fresh  water  has  collected. 

Another  extinct  volcano  of  the  United  States  is  Mt. 
Taylor  in  New  Mexico,  nearly  east  of  the  San  Francisco 
Mountains.  This  mountain  rises  from  the  surface  of  a 
high  table-land,  or,  as  it  is  called  in  this  part  of  the  world,  a 
mesa.  The  surface  of  the  plateau  is  covered  with  a  thick 
lava  stream  from  which  Mt.  Taylor  rises  to  a  height  of 
11,390  feet  above  the  level  of  the  ocean.  This  mesa,  or 
table-land,  is  forty-seven  miles  in  length  from  northwest 
to  southeast,  and  about  twenty-three  miles  in  breadth. 
Its  general  elevation  is  about  8,200  feet.  The  plateau 
rises  about  2,000  feet  above  the  surface  of  the  level  land 
that  surrounds  it.  All  these  2,000  feet  have  been  removed 
by  erosion.  The  table-land  from  which  Mt.  Taylor  rises 
has  not  been  eroded  by  the  action  of  the  rain,  rivers,  and 
other  weathering  agencies  like  the  surface  of  the  country 
surrounding  it,  because  of  a  covering  of  lava  that  has  been 
spread  over  its  surface  to  a  depth  of  about  300  feet. 

Mt.  Taylor  is  formed  almost  entirely  of  lava  that  has 
escaped  through  a  single  opening  and  has  built  up  a  high 
cone  around  it.  The  volcano  is  now  quite  extinct,  so  that 
the  original  form  of  the  mountain  has  been  greatly 
changed  by  erosion. 

You  will  remember,  when  we  were  discussing  the  general 
subject  of  volcanoes,  in  the  beginning  of  this  book,  that 


108         VOLCANOES  AND  EARTHQUAKES 

we  spoke  of  volcanic  mountains  being  bottled  up  after  an 
eruption,  by  the  hardening  of  the  lava  which  remained  in 
the  crater  and  the  tube  that  connects  the  crater  with  the 
place  from  which  the  lava  had  been  derived.  We  then 
spoke  of  this  hardened  mass  being  known  as  a  volcanic 
plug,  or  stopper,  explaining  how  the  volcano  could  never 
again  erupt  through  its  old  crater  unless  it  could  develop 
sufficient  force  to  blow  out  or  remove  this  stopper. 

Now  besides  the  crater  at  the  top  of  Mt.  Taylor  there 
were  several  others  in  the  eroded  region  surrounding  the 
mesa,  or  high  table-land,  from  which  Mt.  Taylor  rises. 
When,  therefore,  the  erosion  which  removed  the  2,000 
feet  of  rocks  on  all  portions  of  the  old  mesa  that  were  not 
protected  by  the  coating  of  lava,  these  old  mountain  plugs 
were  too  hard  to  be  worn  away  or  eroded,  and  were, 
therefore,  left  projecting  into  the  air  like  vast  pyramids. 

If  you  should  ever  visit  Mt.  Taylor  and  should  go  to 
the  eastern  border  of  this  mesa,  and  look  over  the  eroded 
plain,  you  would  see  in  the  lowlands  a  part  of  the  places 
from  which  the  2,000  feet  of  matter  have  been  slowly 
eroded.  Button  describes  the  beautiful  panorama  that 
is  to  be  seen  as  follows: 

"The  edge  of  the  mesa  suddenly  descends  by  a  succes- 
sion of  ledges  and  slopes,  nearly  2,000  feet  into  the  rugged 
and  highly  diversified  valley-plain  below.  The  country 
beneath  is  a  medley  of  low  cliffs  and  bluffs,  showing  the 
browns  and  pale  yellows  of  the  Cretaceous  sandstones 
and  shales.  Out  of  this  confused  patchwork  of  bright 
colors  rise  several  objects  of  remarkable  aspect.  They 
are  apparently  inaccessible  eyries  of  black  rock,  and  at  a 
rough  guess,  by  comparison  with  the  known  altitudes  of 
surrounding  objects,  their  heights  above  the  mean  level 
of  the  adjoining  plain  may  range  from  800  to  1,500  feet. 
The  blackness  of  their  shade  may  be  exaggerated  by  con- 


UNITED  STATES  VOLCANOES  109 

trast  with  the  brilliant  colors  of  the  rocks  and  soil  out  of 
which  they  rise,  but  their  forms  are  even  more  striking." 

These  black  piles  are  the  necks  or  lava  plugs  of  extinct 
volcanoes.  They  rise  above  the  level  of  the  plain  because, 
being  harder  than  the  surrounding  rocks,  they  have  re- 
sisted erosion.  In  some  cases  these  necks  or  plugs  have 
been  converted  by  shrinkage,  on  cooling,  into  beautiful 
columns,  somewhat  of  the  type  of  the  basaltic  columns 
of  the  Giant's  Causeway.  It  would  be  difficult  to  count 
the  number  of  volcanic  necks  that  can  be  seen  near  the 
edge  of  the  mesa.  One's  attention  is  at  once  attracted  to 
some  dozen  of  these  piles,  which  are  especially  striking  on 
account  of  their  great  size,  and  ominous  black  color,  but 
the  number  is  by  no  means  limited  to  this  dozen.  There 
are  hundreds  of  them. 

Fig.  19  gives  some  idea  of  a  part  of  the  view  from  the 
edge  of  the  mesa,  and  Fig.  20  the  appearance  of  two  of 
these  volcanic  necks. 

But  besides  high  volcanic  mountains  such  as  the  San 
Francisco  Mountains  and  Mt.  Taylor,  there  are,  in  different 
parts  of  the  United  States,  to  be  found  fragments  of  huge 
craters  from  which,  in  the  geological  past,  immense 
quantities  of  lava  have  escaped.  In  some  instances  these 
craters  are  but  fragments  of  huge  craters,  that,  like  the 
crater  of  Mt.  Somma,  in  Vesuvius,  have  been  nearly  com- 
pletely blown  away  by  some  unrecorded  explosion  during 
the  far  past. 

A  crater  of  this  type,  known  as  Ice  Springs  Crater,  is 
situated  in  the  desert  valley  west  of  the  Wahsatch  Moun- 
tains, some  125  miles  south  of  Salt  Lake  City,  Utah. 
This  crater  is  especially  interesting  from  the  fact  that  it 
occupies  a  position  on  a  plain  that  was  formed  by  the  depo- 
sition of  sediment  in  an  immense  lake  that  covered  this 
part  of  the  United  States  very  long  before  man  lived  on 


110  VOLCANOES  AND  EARTHQUAKES 


UNITED  STATES  VOLCANOES 


111 


the  earth.    We  are  alluding  to  Lake  Bonneville,  a  lake 
that   existed  in  a  geological  time  known  as  the  Glacial 


From  U.  S.  Geological  Survey 

FIG.  20.     VOLCANIC  NECKS,  EDGE  OF  MESA  AT  MT.  TAYLOR 


Epoch.  This  lake  occupied  the  territory  now  filled  by  the 
Great  Salt  Lake  of  Utah,  but  towards  the  close  of  the  Gla- 
cial Epoch  it  was  immensely  larger  than  it  is  now.  This 
can  be  shown  not  only  by  the  presence  of  shore  lines,  that 
are  clearly  marked  on  the  sides  of  the  surrounding  moun- 
tains, but  also  by  the  ancient  lake  beaches,  and  deltas, 
that  are  common  in  the  district,  so  that  instead  of  there 
being  the  comparatively  limited  area  of  Great  Salt  Lake 
as  marked  on  the  maps  of  to-day  there  was  a  lake  that 
had  an  area  of  19,750  square  miles,  that  covered  an  area 
on  which  at  least  200,000  people  dwell. 

A  similar  lake,  known  as  Lake  Lehontan,  existed  at  the 


112        VOLCANOES  AND  EARTHQUAKES 

same  time,  covering  large  areas  in  the  western  parts  of 
Nevada. 

Coming  now  to  Ice  Springs  Craters  in  Utah,  we  find 
here  three  small  craters  formed  of  scoria  and  lapilli 
(volcanic  ashes  consisting  of  small  angular  stony  frag- 
ments). Near  them  lies  a  fragment  of  a  much  larger 
crater  known  as  the  Crescent.  In  some  respects  this  crater 
was  not  unlike  the  crater  of  Somma  that  surrounded  Mt. 
Vesuvius.  It  was  not,  however,  as  large,  having  a  di- 
ameter of  only  2,200  feet.  From  these  craters  streams  of 
basalt  flowed  until  they  covered  considerable  areas. 

A  still  more  recent  crater  known  as  Tabernacle  Crater 
is  situated  four  miles  south  of  the  Ice  Springs  Crater. 
Tabernacle  Crater  takes  its  name  from  the  building 
known  in  Salt  Lake  City  as  the  Tabernacle.  According 
to  Gilbert,  this  crater  was  formed  at  a  time  when  Lake 
Bonneville  stood  at  a  comparatively  low  level,  or  when 
the  water  was  only  from  fifty  to  seventy-five  feet  above 
the  bottom  of  the  valley  on  which  the  crater  now  stands. 
At  that  time  an  explosive  volcanic  eruption  occurred  on 
the  bottom  of  the  lake,  and  the  rim  of  the  crater,  built  up 
by  this  explosion,  was  gradually  pushed  above  the  surface 
of  the  lake,  so  as  to  shut  out  its  waters. 

Extinct  volcanic  craters,  not  unlike  those  of  Utah, 
occur  also  near  Ragtown,  in  Nevada,  in  a  district  known 
as  the  Carson  Valley  Desert,  in  one  of  the  broadest  areas 
of  what  was  once  Lake  Lahontan.  Ragtown  is  twenty- 
two  miles  southwest  of  Wadsworth  on  the  Central  Pacific 
Railroad.  At  the  present  time  there  are  two  circular 
depressions  or  volcanic  craters  filled  with  pools  of  strongly 
alkaline  water  known  as  the  Ragtown  Pond,  or  Soda 
Lake.  The  large  lake  covers  an  area  of  268£  acres.  Its 
greatest  diameter  is  over  4,000  feet.  Without  going  into 
a  detailed  description  it  will  suffice  to  say  that  the  larger 


UNITED  STATES  VOLCANOES  113 

crater  probably  was  destroyed  by  an  explosive  volcanic 
eruption. 

Another  intensely  alkaline  lake  that  fills  an  extinct 
volcanic  crater  is  the  Mono  Lake,  situated  in  Mono  Valley 
in  California  at  the  eastern  base  of  the  Sierra  Nevadas.  It 
has  an  area  of  about  200  square  miles.  The  centre  of  the 
lake  has  two  small  islands  named  Pacha  and  Negit.  Im- 
mediately south  of  Mono  Lake  are  a  number  of  craters 
that  occupy  portions  of  what  was  once  apparently  a 
fissure  extending  in  a  general  north  and  south  direction. 
The  highest  of  these  craters  are  in  the  neighborhood  of 
2,500  feet. 

But  leaving  these  inconspicuous  craters,  let  us  briefly 
examine  some  of  the  higher  mountain  peaks  of  the  United 
States  that  are  of  volcanic  origin.  One  of  the  most  con- 
spicuous of  these  is  Mt.  Shasta.  This  mountain  is  situated 
in  California,  at  the  northern  end  of  the  Sierra  Nevadas. 
It  has  a  height  of  14,350  feet.  It  is  a  snow-clad  mountain 
of  a  conical  form,  and  is  a  conspicuous  object  in  the  land- 
scape, because  it  stands  alone. 

Mt.  Shasta  is  a  double-coned  mountain.  Besides  the 
cone  on  its  summit  there  is  a  well-developed  cone  known 
as  Shastina  on  the  western  side  of  the  mountain,  2,000 
feet  lower  than  the  main  summit. 

There  are  well-defined  lava  streams  on  the  slopes  of 
Mt.  Shasta.  One  of  these,  which  issued  from  the  southern 
side  of  the  mountain  at  an  elevation  of  5,500  feet,  divided 
into  two  streams.  One  of  these  streams  is  twelve  miles  in 
length.  The  other  entered  the  canyon  of  the  Sacramento 
River,  thus  displacing  the  water. 

Coming  now  to  the  Cascade  Mountains,  in  Oregon  and 
Washington,  we  will  find  in  them  a  number  of  giant  peaks 
of  volcanic  origin.  The  most  important  of  these  are  in 
regular  order  from  south  to  north,  as  follows :  Mt.  Pitt,  9,760 

H 


114         VOLCANOES  AND  EARTHQUAKES 

feet;  Mt.  Mazana,  8,223;  Mt.  Union,  7,881;  Mt.  Scott,  7,123; 
Three  Sisters,  Mt.  Jefferson,  10,200,  and  Mt.  Hood,  11,225, 
in  Oregon;  Mt.  Adams,  9,570;  Mt.  St.  Helen's,  9,750;  Mt. 
Rainier,  14,525,  and  Mt.  Baker  in  Washington,  10,877. 

Nearly  all  these  mountains  have  craters  either  on  their 
summits  or  on  their  sides.  They  are  extinct  volcanic 
mountains,  that  were,  for  the  most  part,  thrown  up  during 
the  Tertiary  Geological  Period,  so  that  they  have  all  been 
greatly  affected  by  erosion. 

One  of  the  most  remarkable  of  the  above  volcanic 
mountains  is  Mt.  Mazana,  in  Oregon.  This  mountain  has 
on  its  summit  an  approximately  circular  cavity  from  five 
to  six  miles  in  diameter,  that  is  occupied  by  a  lake  of  water 
known  as  Crater  Lake.  This  lake  is  6,239  feet  above  the 
level  of  the  sea,  and  has  a  depth  of  1,975  feet.  It  is  sur- 
rounded by  nearly  vertical  walls  ranging  from  900  to 
2,200  feet  deep,  so  that  the  vast  caldera  of  which  this  great 
depression  consists  has  a  depth  of  at  least  4,000  feet. 

Mt.  Pitt,  situated  about  sixty  miles  north  of  Mt.  Shasta, 
in  southern  Oregon,  has  a  regularly  shaped  volcanic  cone, 
and  the  remnant  of  a  crater  at  its  summit.  The  Three 
Sisters  and  Mt.  Jefferson  lie  to  the  north  of  Mt.  Pitt. 
Like  the  others  they  are  ancient  volcanic  mountains. 
But  little  is  accurately  known  concerning  them. 

Mt.  Hood,  11,225  feet  high,  rises  from  the  crest  of  the 
Cascade  range  in  Northwest  Oregon,  about  twenty-five 
miles  south  of  the  Columbia  River.  Mt.  Hood  is  an  ex- 
ceedingly majestic  mountain.  At  its  summit  there  are 
only  portions  of  the  walls  of  the  original  crater.  When 
ascended  in  1888,  streams  of  sulphur  vapor  were  escaping 
from  fumaroles  on  its  northeastern  slopes,  at  an  elevation 
of  8,500  feet  above  the  sea. 

Mt.  Adams  and  Mt.  St.  Helen's  lie  to  the  north  of  Mt. 
Hood.  Mt.  Adams  about  sixty  miles  to  the  north,  and 


UNITED  STATES  VOLCANOES  115 

beyond  this,  Mt.  St.  Helen's.  Accurate  information  con- 
cerning the  summit  of  Mt.  Adams  is  still  lacking.  Mt. 
St.  Helen's  in  Washington  has  more  of  a  conical  summit. 
Russell  states  that  according  to  frontiersmen,  St.  Helen's 
has  been  in  a  state  of  activity  within  the  past  fifty  years. 
A  French-Canadian  asserts  that  the  mountain  was  in 
actual  eruption  during  -the  winter  of  1841-43,  that  at  this 
date  the  light  from  the  volcano  was  sufficiently  bright  to 
enable  one  to  see  and  pick  up  a  pin  in  the  grass  at  midnight 
near  his  cabin  some  twenty  miles  distant.  Mt.  St.  Helen's 
was  ascended  in  1889,  when  fumaroles  were  found  on  the 
northeast  side. 

Mt.  Rainier  in  Washington  is  plainly  visible  from  Puget 
Sound.  It  is  a  most  magnificent  mountain.  The  sum- 
mit has  a  bowl-shaped  crater,  of  an  almost  perfectly  cir- 
cular form.  The  inside  of  the  crater,  when  last  ascended, 
was  filled  to  within  thirty  or  thirty-five  feet  of  its  rim 
with  ice  and  snow.  There  was,  however,  evidences  of 
heat,  since  numerous  jets  of  steam  were  seen  issuing 
from  its  interior  rim. 

Mt.  Baker,  Washington,  is  the  northernmost  of  the 
volcanoes  of  the  Cascade  Mountains,  south  of  the  bound- 
ary line  between  the  United  States  and  Canada.  But  little 
is  known  of  this  mountain.  The  summit  appears  as  a  coni- 
cal peak  from  Puget  Sound,  so  that  its  form  would  seem 
to  show  that  it  is  of  volcanic  origin.  According  to  Gibbs, 
officers  of  the  Hudson  Bay  Company,  as  well  as  the  In- 
dians, declared  that  Mt.  Baker  was  in  eruption  in  1843, 
when  it  broke  out  at  the  same  time  as  Mt.  St.  Helen's, 
covering  the  country  with  ashes. 

There  are  but  few  volcanoes  in  the  Rocky  Mountains 
which  extend  from  north  to  south  through  the  United 
States  at  a  considerable  distance  to  the  east  of  the  Sierra 
Nevadas  and  Cascade  Ranges.  The  Spanish  Peaks, 


116         VOLCANOES  AND  EARTHQUAKES 

situated  in  the  southeastern  part  of  Colorado  about  sixty 
miles  south  of  Pueblo,  are  the  remains  of  ancient  volcanoes. 
Two  of  the  most  prominent  of  these  peaks  rise  from  12,720 
to  13,620  feet  above  the  sea. 

We  shall  make  no  effort  to  attempt  to  describe  the 
volcanic  mountains  that  may  exist  in  those  portions  of 
the  Rocky  Mountain  Ranges  or  the  Cascade  Range  lying 
in  Canada.  Comparatively  little  is  known  of  them,  but 
inasmuch  as  volcanic  activity  has  been  manifested  in 
Alaska,  it  would  seem  highly  improbable,  as  Russell  re- 
marks, that  volcanoes  should  suddenly  cease  at  the  north- 
ern boundaries  of  the  United  States  and  then  begin  again 
at  the  most  southern  part  of  Alaska.  It  will  be  sufficient 
to  say  that  Mt.  Edgecome,  situated  on  an  island  in  the 
neighborhood  of  Sitka,  is  of  volcanic  origin,  and  that 
the  Aleutian  Islands,  beginning  at  Alaska  on  the  east  at 
the  head  of  Cook's  Inlet,  extend  westward  through  the 
Peninsula  of  Alaska  to  the  Peninsula  of  Kamtschatka  for 
a  distance  of  nearly  1,600  miles.  This  belt,  which  is  called 
by  Russell  "the  Aleutian  Volcanic  Belt,"  contains  nu- 
merous volcanoes  that  are  known  to  have  been  active  in 
historical  times. 

Mt.  Wrangell,  on  the  Copper  River,  200  miles  northeast 
of  the  head  of  Cook's  Inlet,  is  a  lofty  volcanic  mountain 
that  is  said  to  have  been  in  eruption  in  1819,  and  at  the 
time  of  last  report  was  still  throwing  out  columns  of  steam. 
While  much  remains  to  be  ascertained  about  the  volcanoes 
of  the  Aleutian  Islands,  it  would  appear  that  there  are 
active  volcanoes  on  twenty-five  of  these  islands,  on  which 
some  forty-eight  craters  have  been  found.  Eruptions* 
are  common  in  the  district. 


CHAPTER  XI 

THE    CATASTROPHE    OF    MARTINIQUE    AND    THE    VOLCANIC 
ISLANDS    OF    THE    LESSER    ANTILLES 

The  West  Indies  Island  chain  consists  of  two  groups  of 
islands;  i.  e.,  the  Greater  Antilles,  including  Cuba,  Ja- 
maica, Hayti,  and  Porto  Rico,  on  the  west,  and  the  chain 
of  the  Lesser  Antilles  on  the  east. 

The  Lesser  Antilles  consists  of  two  parallel  chains,  the 
westernmost  of  which  is  for  the  greater  part  mountainous 
with  peaks  several  thousand  feet  in  height.  All  these 
islands  are  volcanic.  The  chain  on  the  east  consists  of 
low,  calcareous  rocks,  or  rocks  consisting  largely  of  lime. 

In  the  western  chain  the  islands  beginning  on  the  south 
are,  Grenada,  St.  Vincent,  St.  Lucia,  Martinique,  Domi- 
nica, Guadeloupe,  Montserrat,  Nevis,  and  St.  Eustace, 
while  in  the  calcareous  chain  are  found  the  Tobago, 
Barbadoes,  and  others. 

Prior  to  1902,  the  greatest  volcanic  eruption  in  this 
part  of  the  world  occurred  on  the  island  of  St.  Vincent, 
with  the  volcano  of  Soufriere.  Although  the  forces  dis- 
played were  exceedingly  great,  yet  they  become  insig- 
nificant when  compared  with  the  appalling  eruption  that 
took  place  in  Martinique  only  a  short  time  ago;  namely, 
May  the  8th,  1902,  when  the  volcano  of  Mt.  Pelee,  situ- 
ated on  the  northwestern  part  of  the  island,  burst  into 
an  eruption  so  terrible  that  in  destruction  of  life  it  far 
exceeded  the  eruption  of  Krakatoa,  although  the  amount 
of  energy  causing  the  eruption  was  much  smaller. 
[117] 


118        VOLCANOES  AND  EARTHQUAKES 


00 


VOLCANIC  CATASTROPHES  119 

Heilprin,  in  a  book  called  "Mt.  Pele"e  and  the  Tragedy 
of  Martinique,"  from  whom  most  of  the  information  of 
this  chapter  has  been  obtained,  calls  attention  to  the  fact 
that  before  the  eruption  of  Pelee  there  were  plenty  of 
warnings  for  those  intelligent  enough  to  note  them. 
For  two  or  three  weeks  prior  to  May  8th,  1902,  the  volcanic 
activity  of  Pelee  had  been  rapidly  increasing,  the  moun- 
tain throwing  out  clouds  of  ashes  and  sulphurous  vapors 
from  its  crater.  By  April  25th  the  sulphurous  vapors 
had  so  increased  in  quantity  as  to  make  breathing  diffi- 
cult in  St.  Pierre.  The  ashes  fell  on  the  surrounding 
country  and  by  the  2d  of  May  had  so  covered  the  streets 
of  St.  Pierre  as  to  stop  traffic. 

Three  days  later,  May  6th,  shortly  before  noon,  an 
avalanche  of  mud  poured  down  the  slopes  of  the  moun- 
tain with  the  rapidity  of  an  express  train.  These  torrents 
of  mud  and  water  deluged  the  towns  and  villages  in  the 
neighborhood.  The  activity  of  Mt.  Pelee  increased  until 
the  morning  of  May  8th,  1902,  when,  almost  at  exactly 
8  A.  M.,  an  eruption  occurred,  so  terrible  in  its  effects 
that  in  two  minutes  the  city  of  St.  Pierre  was  almost 
completely  destroyed. 

St.  Pierre,  the  principal  town  of  Martinique,  is  situated 
on  the  island  of  Martinique,  on  the  northwestern  coast, 
about  ten  miles  southwest  of  Mt.  Pelee.  St.  Pierre  was 
settled  as  far  back  as  1635.  It  is  situated  on  an  open 
roadstead  without  any  harbor. 

That  there  were  many  points  of  resemblance  between 
the  position  of  St.  Pierre  and  the  destroyed  city  of  Pom- 
peii will  be  recognized  as  the  description  of  the  catas- 
trophe is  given. 

St.  Pierre  was  a  beautiful  city,  and  formed  the  natural 
outlet  to  one  of  the  richest  districts  in  Martinique  for  the 
production  of  sugar  cane  and  cocoa,  It  contained  many 


120         VOLCANOES  AND  EARTHQUAKES 

fine  houses,  the  homes  of  planters,  wealthy  bankers, 
merchants,  and  shippers,  who,  besides  their  regular 
houses  in  the  city,  had  constructed  handsome  villas  on 
heights  on  the  outskirts  of  the  city.  The  houses  were  to 
a  great  extent  one  or  two  stories  in  height,  and  were  in 
many  cases  surrounded  by  fine  gardens.  The  city  ex- 
tended along  the  coast  for  about  two  miles.  The  streets 
were  well  lighted. 

The  eruption  of  Mt.  Pele"e  on  May  8th,  1902,  was  of  a 
very  unusual  character,  containing  a  feature  that — with 
the  exception  of  a  volcanic  eruption  of  Soufriere,  a  vol- 
canic mountain  on  the  neighboring  island  of  St.  Vincent, 
and  an  eruption  of  Kilauea  in  Hawaii — so  far  as  I  am 
aware,  never  before  occurred.  This  was  a  blast  of  highly 
heated  air,  mingled  with  white  hot  or  incandescent  dust, 
that  swept  down  the  side  of  the  mountain  with  a  velocity 
of  one  or  two  miles  per  minute,  or  possibly  more. 

Nearly  all  of  the  people  in  St.  Pierre  were  killed.  From 
the  appearance  of  the  bodies  it  seemed  that  death  was 
practically  instantaneous,  and  was  due  either  to  scorch- 
ing or  burning,  or  asphyxiation  by  the  breathing  of  highly 
heated  air.  The  number  of  people  so  killed,  including 
almost  the  entire  population  of  St.  Pierre,  as  well  as  a  num- 
ber of  adjoining  settlements,  was  not  less  than  30,000. 

The  zone  of  absolute  destruction  was  limited  to  an  area 
the  extent  of  which  did  not  greatly  exceed  eight  or  nine 
square  miles.  On  the  outskirts  of  this  zone  the  destruc- 
tion, though  considerable,  was  less  complete. 

There  was  almost  an  entire  absence  of  great  earthquake 
shocks  during  the  eruption. 

Following  the  terrible  eruption  of  May  8th  were  a  num- 
ber of  less  violent  eruptions  on  May  20th,  26th,  June  6th, 
July  9th,  and  August  31st.  According  to  Heilprin  these 
eruptions  were  of  the  same  character  as  that  of  May  8th. 


VOLCANIC  CATASTROPHES  121 

There  has  been  considerable  discussion  as  to  the  exact 
causes  of  the  tornadic  incandescent  blast  that  caused  the 
awful  destruction  of  life.  Without  entering  this  discus- 
sion it  is  sufficient  to  say  that  it  is  now  generally  considered 
that  the  blast  consisted  of  highly  heated  air,  and  super- 
heated steam  loaded  with  great  quantities  of  finely 
divided  red  hot  or  even  white  hot  dust  particles. 

While,  perhaps,  the  force  producing  the  awful  eruption 
of  Mt.  Pelee  was  greatly  excelled  in  the  case  of  many  other 
volcanic  eruptions;  such  as  Papandayang,  in  1772; 
Asamayama,  in  1783;  Skaptar  Jokul,  in  1783;  Tomboro, 
in  1815;  Cosegiima,  in  1835;  and  Krakatoa,  in  1883;  yet, 
in  the  words  of  Heilprin,  "in  intensity  and  swiftness  of  its 
death-dealing  blast  ...  the  eruption  of  May  8th,  and 
of  later  dates,  stands  unique  in  records  of  volcanic  mani- 
festations." 

While  the  amount  of  ashes  that  accompanied  the  blast 
of  white  hot  steam  and  air  was  comparatively  small,  yet 
during  the  time  between  this  and  the  subsequent  erup- 
tions, the  amount  of  ashes  that  were  thrown  from  the 
surface  of  Mt.  Pelee  was  exceedingly  great. 

According  to  Russell,  in  a  paper  on  the  volcanic  erup- 
tions of  Martinique  and  St.  Vincent,  in  1902,  the  amount 
of  ashes  and  solid  matter  generally  thrown  out  from  the 
crater  of  Mt.  PelSe  would  be  equal  to  40,000,000  cubic 
feet  every  minute,  or  one  and  a  half  times  the  sediments 
discharged  by  the  Mississippi  in  the  course  of  a  whole 
year. 

According  to  Heilprin,  however,  the  actual  amount 
of  dust  thrown  from  the  crater  of  Mt.  Pelee  was,  probably, 
500  times  greater  than  the  amount  discharged  by  the 
Mississippi  River  in  the  course  of  a  year,  and,  consequently, 
considerably  greater  than  that  of  all  the  rivers  of  the 
world  combined,  or,  as  he  says: 


122          VOLCANOES  AND  EARTHQUAKES 

"Mont  Pele"e  has  now  been  in  a  condition  of  forceful 
activity  for  upwards  of  two  hundred  days;  can  we  assume 
that  during  this  time  it  may  have  thrown  out  a  mass  of 
material  whose  cubical  contents  are  hardly  less  than  a 
quarter  of  the  area  of  Martinique  as  it  now  appears  above 
the  waters?  One  is,  indeed,  almost  appalled  by  the  mag- 
nitude of  this  work,  and  yet  the  work  may  even  be  very 
much  greater  than  is  here  stated.  We  ask  ourselves  the 
questions,  what  becomes  of  the  void  that  is  being  formed 
in  the  interior?  What  form  of  new  catastrophe  does  it 
invite?  There  can  be  no  answer  to  a  question  of  this 
kind — except  in  the  future  happening  that  may  be  asso- 
ciated with  this  special  condition.  But  geologists  must 
take  count  of  the  force  as  being  one  of  greatest  potential 
energy,  whose  relation  to  the  modelling  and  the  shaping 
of  the  destinies  of  the  globe  is  of  far  greater  significance 
than  has  generally  been  conceived." 

A  curious  circumstance  connecied  with  the  eruption  of 
Mt.  Pelee  was  the  most  pronounced  electric  and  magnetic 
disturbances.  Moreover,  as  in  the  case  of  the  eruption  of 
Krakatoa,  there  were  the  same  after  glows  or  red  sunsets 
and  sunrises  due  to  the  presence  of  fine  volcanic  dust  in 
the  higher  regions  of  the  air.  These  phenomena  were 
observed  over  widely  separated  areas. 

It  appears  that  this  great  eruption  in  Martinique  was 
preceded  by  severe  earthquakes  in  the  northern  part 
of  South  America,  especially  in  Colombia  and  Vene- 
zuela. The  most  marked  was  the  great  earthquake 
which  on  April  18th  destroyed  the  city  of  Guatamaula; 
this  was,  perhaps,  the  most  destructive  earthquake  that 
has  occurred  in  the  Western  Hemisphere  since  the  great 
earthquake  of  1812,  that  destroyed  the  city  of  Caracas. 
Indeed,  Professor  Milne  suggests  that  it  was  this  earth- 
quake that  brought  about  the  eruption  of  Mt.  Pele"e, 


VOLCANIC  CATASTROPHES  123 

Soufriere,  on  the  island  of  St.  Vincent,  had  a  great  erup- 
tion on  May  7th,  1902,  one  day  before  the  awful  eruption 
of  Mt.  Pelee.  No  lava  flowed  during  this  eruption.  There 
were,  however,  great  discharges  of  mud,  due  to  a  lake  that 
before  the  eruption  filled  the  top  of  a  depression  known 
as  the  old  crater  which  lay  southwest  of  a  new  crater,  or 
the  crater  that  was  formed  during  the  eruption  of  1812. 
The  old  crater  was  nine-tenths  of  a  mile  across  from  east 
to  west,  and  eight-tenths  of  a  mile  from  north  to  south. 
The  depth  to  the  crater  floor  was  from  1,000  to  2,400  feet. 
The  surface  of  the  new  and  shallow  boiling  lake  which 
occupied  the  deepest  part  of  the  floor  during  the  latter 
part  of  May,  and  from  June  to  August,  was  estimated  to 
be  only  1,200  feet  above  the  level  of  the  sea.  The  sheet 
of  water  that  occupied  it  before  the  eruption  being  several 
hundred  feet  higher. 

Soufriere  did  not  fail  to  give  warnings  of  its  coming 
eruption.  Rumblings  were  heard  two  days  before  the 
explosion.  On  May  5th,  1902,  fishermen  who  crossed  the 
lake  noticed  that  the  water  was  disturbed  and  agitated. 
On  the  Tuesday  following,  May  6th,  great  clouds  were 
thrown  out  during  the  afternoon,  and  the  volcano  was 
illumined  by  a  reddish  glare  of  fire.  The  first  explosion 
was  heard  shortly  before  two  o'clock  on  the  following  day 
and  the  volcano  burst  into  activity.  The  explosions,  to- 
gether with  great  discharges  of  pumice,  ashes,  and  boul- 
ders, followed  one  another  rapidly.  A  column  of  steam 
was  shot  up  into  the  air  for  a  height  of  30,000  feet.  The 
severest  paroxysm  came  shortly  after  ten  A.  M.,  and  was 
succeeded  by  others  nearly  as  violent  during  the  next 
few  hours.  By  this  time  a  reddish  curtain  of  clouds 
nearly  shut  out  the  island  from  view,  and  rapidly  ad- 
vanced over  the  land  and  descended  on  the  sea.  This 
eruption  caused  a  loss  of  life  of  about  1,350, 


124         VOLCANOES  AND  EARTHQUAKES 

This  eruption  of  Mt.  Soufriere  was  accompanied  by 
the  same  tornadic  blast  of  glowing  air.  There  was  not, 
however,  any  single  blast  quite  as  severe  as  that  which 
attended  the  eruption  of  Pel<§e  on  May  8th,  1902. 


CHAPTER  XII 

SOME    OTHER    NOTED    VOLCANIC    MOUNTAINS 

Since  the  limits  of  our  book  will  prevent  any  further 
description  of  volcanic  districts  or  regions,  we  must  con- 
tent ourselves  with  descriptions  of  some  of  the  noted  of 
the  remaining  volcanoes,  although  many  we  will  thus 
omit  contain  great  wonders. 

As  we  have  already  seen  from  the  description  of  Kra- 
katoa,  the  island  of  Java  near  which  Krakatoa  is  situated 
is  especially  noted  not  only  for  the  great  number  of  its 
volcanic  mountains,  but  also  for  the  frequency  and  se- 
verity of  their  eruptions. 

Perhaps  the  most  destructive  eruption  of  any  of  the 
volcanic  mountains  of  Java  was  of  a  volcanic  mountain 
called  Papandayang.  This  volcano,  situated  on  the 
southern  coast  of  the  island,  is  7,034  feet  in  height,  and 
was  in  eruption  in  1772.  According  to  Scrope,  from  whom 
the  details  of  this  eruption  have  been  obtained,  two 
others  of  the  many  volcanoes  on  Java,  situated  at  184 
and  352  geographical  miles  respectively  from  Papanda- 
yang, broke  out  at  the  same  time  into  active  eruption, 
although  several  intervening  cones  were  undisturbed. 

The  eruption  of  Papandayang  was  of  the  explosive  type, 
a  large  part  of  the  mountain  being  broken  off  by  the  great 
force  of  the  eruption,  and  its  materials  scattered  far  and 
wide  over  the  surrounding  country.  During  this  eruption 
forty  villages  with  their  inhabitants  were  buried  by  great 
showers  of  ashes.  An  area  of  fifteen  by  six  miles  was  left 
[125] 


126          VOLCANOES  AND  EARTHQUAKES 

in  the  shape  of  a  huge  pit  by  the  great  eruption.  It  was 
at  first  believed  by  some  that  this  pit  was  due  to  the  actual 
sinking  in  of  the  ground,  but  a  more  careful  study  has 
shown  that  it  was  in  reality  caused  by  the  great  force  of 
the  eruption,  being,  in  point  of  fact,  a  vast  explosive  crater 
that  was  formed  by  the  expulsion  of  the  materials  that 
formerly  filled  it.  Some  idea  of  the  great  extent  of  this 
eruption  of  Papandayang  may  be  had  by  the  size  of  this 
huge  crater  that  was  six  by  fifteen  miles  in  diameter. 

Another  great  volcanic  mountain  in  Java  that  had  a 
terrific  eruption  was  Galungoon,  or  Galung  Gung.  Ac- 
cording to  Lyell,  from  whom  the  facts  of  this  eruption 
have  been  obtained,  prior  to  this  eruption  the  slopes  of 
the  mountain  were  highly  cultivated  and  densely  popu- 
lated. There  was  a  circular  pit  or  crater  on  the  summit  of 
the  mountain,  but  there  had  been  no  traditions  of  any 
eruptions  prior  to  1822. 

In  July,  1822,  the  waters  of  the  Kunir  River,  one  of 
the  small  rivers  that  flow  down  the  slopes  of  the  mountain, 
were  observed  to  become  hot  and  turbid.  On  the  8th  of 
October,  1822,  a  terrific  explosion  was  suddenly  heard, 
accompanied  by  great  earthquake  shocks,  when  immense 
columns  of  hot  water  and  boiling  mud,  mixed  with  burn- 
ing brimstone,  ashes,  and  lapilli,  were  thrown  violently 
like  a  great  waterspout  from  the  opening  in  the  moun- 
tain, with  such  enormous  violence  that  great  quantities 
fell  across  the  River  Tandoi,  forty  miles  distant,  while 
the  valleys  in  the  neighborhood  were  filled  with  a  burning 
torrent.  The  rivers  overflowed  their  banks  and  produced 
great  destruction  by  floods  of  burning  and  boiling  materi- 
als that  washed  away  all  the  villages  and  cultivated 
fields  in  their  path.  During  this  eruption  an  extended 
area  was  covered  with  boiling  mud  in  which  were  com- 
pletely buried  the  bodies  of  many  of  those  who  perished. 


OTHER  VOLCANOES  127 

So  great  was  the  violence  with  which  the  boiling  mud, 
cinders,  etc.,  were  thrown  out  of  the  mountain  that  they 
entirely  failed  to  fall  on  many  of  the  villages  in  the  imme- 
diate neighborhood,  while  the  more  remote  villages  were 
completely  destroyed  and  buried  out  of  sight  under  the 
mud. 

The  first  eruption  continued  for  nearly  five  hours. 
During  several  days  following  the  eruption,  torrents  of 
rain  fell,  which  produced  floods  in  the  rivers  that  covered 
the  country  far  and  wide  with  thick  layers  of  mud. 

Four  days  after  the  great  eruption,  that  is,  on  the  12th 
of  October,  1822,  a  second  and  still  more  violent  erup- 
tion occurred,  when  immense  quantities  of  hot  mud  were 
again  thrown  out  of  the  crater.  Great  blocks  of  hardened 
lava  called  basalt  were  thrown  a  distance  of  seven  miles 
from  the  volcano.  This  eruption  was  accompanied  by  a 
violent  earthquake.  It  was  during  this  eruption  that  a 
huge  piece  of  the  side  of  the  cone  was  blown  out,  not  un- 
like the  case  of  the  Val  del  Bove  on  Mt.  Etna.  The  sur- 
rounding country  was  covered  with  mud.  The  immense 
quantity  of  materials  thus  thrown  out  of  the  side  of  the 
mountain  produced  changes  in  the  courses  of  several  riv- 
ers, thus  causing  great  floods  which  in  the  single  night 
of  October  12th  drowned  2,000  people.  During  these 
eruptions  there  were  114  villages  destroyed,  with  a  total 
loss  of  life  of  about  4,000. 

There  is  a  volcanic  mountain  on  the  island  of  Sumbawa 
that  is  noted  for  the  very  destructive  eruption  that  oc- 
curred on  it  in  April,  1815.  If  you  examine  the  map  of 
the  Sunda  Islands  chain,  you  will  see  that  the  island  of 
Sumbawa  lies  immediately  east  of  a  little  island  called 
Lombock,  about  200  miles  east  of  Java. 

This  eruption  of  Sumbawa  was  of  the  most  frightful 
violence,  and,  indeed,  with  the  exception  of  Krakatoa 


128         VOLCANOES  AND  EARTHQUAKES 

and  Pel6e,  was  one  of  the  greatest  eruptions  in  historic 
times. 

Like  all  great  eruptions,  that  of  Sumbawa  gave  plenty 
of  signs  of  its  coming.  During  April,  1814,  the  volcano 
manifested  considerable  increase  in  its  activity,  and  ashes 
fell  on  the  decks  of  vessels  sailing  past  the  island. 

The  eruption  began  on  April  5th,  1815,  but  reached 
its  greatest  violence  on  the  llth  and  12th  of  April.  Ac- 
cording to  Lyell,  the  sound  of  the  explosion  was  heard  at 
the  island  of  Sumatra  at  a  distance  of  970  geographical 
miles  towards  the  west,  and  in  the  opposite  direction  it 
was  heard  for  a  distance  of  720  miles.  The  destruction 
of  life  was  terrible.  Out  of  a  population  of  12,000  in  the 
province  of  Tomboro,  only  twenty-six  people  escaped  with 
their  lives. 

Like  many  other  great  eruptions  the  shooting  upwards 
of  the  great  column  of  matter  from  the  crater  produced  a 
violent  whirlwind  that  carried  people,  horses,  cattle,  and 
almost  every  movable  object  high  into  the  air,  and  tore 
up  huge  trees  by  their  roots. 

Immense  quantities  of  ashes  fell  over  the  surrounding 
country,  or  were  carried  towards  Java  to  the  west  a  dis- 
tance of  300  miles,  while  on  the  north  they  were  carried 
towards  Celebes  for  a  distance  of  217  miles.  Cinders 
covered  the  ocean  towards  the  west  two  feet  thick  and 
several  miles  in  length,  so  that  ships  could  hardly  make 
their  way  through  them. 

The  darkness  in  Java  produced  by  the  dense  ash  cloud 
was  greater  than  had  ever  before  been  experienced  with 
the  single  exception  of  the  great  eruption  of  Krakatoa. 
A  considerable  quantity  of  this  volcanic  dust  was  carried 
to  the  islands  of  Amboyna  and  Banda,  the  last  named 
island  being  at  a  distance  of  800  miles  east  of  the  volcano. 

This  eruption  of  Sumbawa  was  attended  by  great  lava 


OTHER  VOLCANOES  129 

streams  that  covered  vast  areas  of  the  land  and  afterwards 
poured  into  the  sea. 

As  in  the  case  of  the  explosive  eruption  of  Krakatoa 
great  waves  were  produced  in  the  ocean  all  along  the  coasts 
of  Sumbawa,  and  surrounding  islands.  The  sea  suddenly 
rose  from  two  to  twelve  feet.  A  great  wave  rushed  up 
the  mouths  of  the  rivers,  and  at  the  town  of  Tomboro,  on 
the  west  side  of  Sumbawa,  an  area  of  land  was  sunk  in 
the  waters  and  remained  permanently  covered  by  eigh- 
teen feet  of  water. 

The  most  important  of  the  still  active  volcanoes  of 
Japan  is  Assamayna.  This  mountain  was  in  terrible  erup- 
tion during  the  autumn  of  1783,  when  dense  showers  of 
ashes  thrown  out  of  the  crater  darkened  the  sky,  turning 
the  day  into  night,  and,  falling  on  the  cultivated  fields 
around  the  mountain,  changed  them  into  deserts.  During 
the  eruption  some  forty-eight  villages  were  destroyed  by 
showers  of  ashes  and  red  hot  stones  and  thousands  of 
the  inhabitants  were  either  killed  directly  by  the  stones 
and  ashes,  or  died  from  starvation,  since  their  fields  were 
covered  with  ashes  for  miles  around  to  a  depth  of  from 
two  and  a  half  to  five  feet. 

Another  terrible  eruption  in  Japan  was  in  the  volcanic 
mountain  of  Wunzen,  or  Onzen-Gatake.  This  occurred 
during  1791-93.  During  the  last  eruption  of  this  volcano, 
53,000  people  lost  their  lives,  either  by  reason  of  the  erup- 
tion of  the  volcano,  or  by  huge  waves  set  up  in  the  ocean 
by  an  earthquake. 


CHAPTER  XIII 

JORULLO,  A   YOUNG  VOLCANIC  MOUNTAIN 

You  must  not  suppose  that  when  we  speak  of  Jorullo  as 
a  young  volcanic  mountain  that  we  mean  young  in  the 
sense  that  you  or  I  might  be  called  young,  but  young  as 
regards  mountains;  for  Jorullo,  now  a  great  mountain 
range,  had  no  existence  before  the  year  1759,  and  that 
would  make  the  mountain  a  little  less  than  150  years 
old,  which  so  far  as  mountains  are  concerned  may  properly 
be  regarded  as  quite  young. 

The  story  of  Jorullo  is  very  interesting,  and  affords  an 
excellent  example  of  the  great  scale  on  which  modern 
volcanic  eruptions  take  place  during  historical  times. 

If  you  examine  the  map  of  Mexico  on  page  86  you  will 
see  that  Jorullo  lies  170  miles  southwest  of  the  city  of 
Mexico,  and  108  miles  from  the  Pacific  Ocean,  which  is  the 
nearest  large  body  of  water.  This  mountain  is  of  especial 
interest  because,  if  old  traditions  are  to  be  believed,  it 
was  thrown  up  during  practically  a  single  night.  This 
wonderful  event  took  place  on  an  elevated  plain  or  plateau, 
called  the  Plain  of  Malpais,  that  lies  between  2,000  and 
3,000  feet  above  the  level  of  the  ocean.  The  plain  was 
situated  in  a  part  of  Mexico  that  was  celebrated  for  the 
growth  of  the  finest  cotton  and  indigo  in  the  world.  It 
formed  the  large  estate  of  a  wealthy  planter,  Senor  Pedro 
de  Jorullo,  who  lived  at  his  ease  as  a  wealthy  planter  is  apt 
to  do  in  tropical  countries  like  Mexico. 

Jorullo 's  plantation  was  covered  by  an  especially  fer- 
[130] 


JORULLO  131 

tile  soil,  since  it  was  formed  by  the  deposits  of  volcanic 
ashes,  dust,  tufa,  etc.,  produced,  most  probably,  by 
neighboring  volcanoes  long  before  man  appeared  on  the 
earth,  for  the  plain  of  Malpais  was  bounded  by  hills  that 
were  composed  of  volcanic  materials.  There  had,  how- 
ever, been  no  signs  of  volcanic  activity  in  the  neighbor- 
hood. It  had  indeed  been  quiet,  so  far  as  volcanic  erup- 
tions were  concerned,  since  the  time  of  the  discovery  of 
America  by  Columbus,  until  the  middle  of  the  last  century. 
The  fertile  fields  of  the  Jorullo  plantation  were  watered 
by  two  rivers,  or  as  we  would  probably  call  them,  brooks, 
the  Cuitamba  and  the  San  Pedro. 

Signs  were  not  wanting  of  the  coming  calamity.  During 
June,  1759,  subterranean  sounds  were  heard  of  a  low 
rumbling  character,  which  every  now  and  then  increased 
until  they  resembled  in  intensity  the  sounds  produced  by 
the  firing  of  large  guns.  These  sounds  were  accompanied 
by  earthquake  shocks  that  greatly  terrified  the  people 
and  caused  them  to  flee  from  their  homes.  Nothing, 
however,  occurred,  so,  becoming  accustomed  to  the  noises, 
the  people  returned  to  their  houses.  The  noises  and 
tremblings  ceased  for  over  two  months,  until,  on  the 
29th  of  September,  1759,  they  were  again  heard,  and  a 
terrible  eruption  began.  A  long  fissure  opened  in  the  earth, 
extending  generally  from  northeast  to  southwest.  From 
this  fissure  flames  burst  out,  fragments  of  burning  rock 
and  stone,  together  with  large  quantities  of  ashes  were 
thrown  to  great  heights  in  the  air,  and  were  followed  by 
streams  of  molten  rock.  Six  volcanic  cones  were  formed 
along  the  fissure.  The  highest  of  these  cones  is  what  now 
constitutes  the  volcanic  mountain  of  Jorullo,  which  then 
reached  a  height  of  at  least  1,600  feet  above  the  level  of 
the  plain.  From  its  cone  were  thrown  out  great  quantities 
of  lava  of  the  same  type  as  that  which  escaped  from  the 


132         VOLCANOES  AND  EARTHQUAKES 

craters  of  many  volcanic  islands  such  as  Hawaii  and 
Iceland,  namely,  basaltic  lavas.  This  eruption,  which 
began  on  the  29th  of  September,  1759,  continued  until 
the  month  of  February,  1760. 

The  account  as  above  given  was  obtained  by  Humboldt, 
who  visited  the  country  some  fifty-six  years  after  the  erup- 
tion. This  story  was  told  him  by  the  Indians,  but  was 
also  recorded  in  verse  by  a  Jesuit  priest,  Raphael  Landiva, 
a  native  of  Guatemala.  According  to  the  account  given 
Humboldt  by  the  Indians,  it  appears  that  when  a  long 
time  after  the  eruptions  had  quieted  down,  they  had  re- 
turned to  their  old  homes  with  the  hope  of  cultivating  part 
of  the  grounds,  they  found  the  plains  still  too  hot  to  permit 
their  living  on  them. 

According  to  Lyell,  there  was  around  the  base  of  the 
cone,  spreading  from  them  as  a  centre  over  an  area  of 
some  four  square  miles,  a  convex  mass,  about  550  feet  in 
height,  most  of  the  surface  of  which  was  covered  with 
thousands  of  small  flattish  conical  mounds  from  six  to 
nine  feet  in  height.  These,  together  with  numerous  large 
fissures  that  crossed  the  plain  in  different  directions,  served 
as  points  for  the  escape  of  sulphur  vapors,  as  well  as  for 
the  vapors  of  hot  water. 

During  the  escape  of  lava  from  the  craters  in  1759,  the 
molten  rock,  spreading  over  the  plain,  ran  into  the  chan- 
nels of  the  river  or  brooks  before  named,  driving  out  the 
water.  This  water  reappeared  at  the  base  of  the  mountain 
in  numerous  hot  springs. 

Humboldt  thought  that  the  conical  mountains  had  been 
lifted  or  raised  by  the  formation  of  huge  bubbles  formed 
under  the  lava,  thus  causing  it  to  assume  a  shape  not 
unlike  that  of  a  huge  bladder.  This  opinion,  however, 
has  not  been  accepted  by  geologists  at  the  present  time. 
Scrope  points  out  that  this  was  probably  the  origin  of  the 


JORULLO  133 

little  conical  mounds  that  covered  the  surface  of  the 
principal  conical  mounds  but  was  not,  in  all  probability, 
the  cause  of  the  mound  itself.  He  says: 

"With  regard  to  the  disputed  question  as  to  the  origin 
of  the  raised  plain  of  the  Malpais,  M.  de  Saussure,  the  last 
and  most  trustworthy  visitor,  entirely  confirms  the  opin- 
ion which  I  ventured  to  proclaim  in  1825,  that  Humboldt 
was  mistaken  in  supposing  it  to  have  been  'blown  up 
from  beneath  like  a  bladder,'  and  that  it  is  merely  an 
ordinary  current  of  lava,  which,  owing  to  its  very  imper- 
fect liquidity  at  the  time  of  its  issue  from  the  volcanic 
vent,  as  well  as  to  the  overflow  of  one  sheet  or  stream 
upon  another,  had  acquired  great  thickness  about  its 
source,  gradually  thinning  off  towards  the  outer  limit  of 
the  elliptical  area  it  covered." 

If  you  have  been  able  to  follow  the  above  you  will 
see  that  Mr.  Scrope  means  that  in  his  opinion  the  cone  of 
Jorullo  is  a  lava  cone  like  that  we  have  already  studied  on 
Mt.  Loa  or  Mt.  Kilauea,  or,  in  other  words,  that  the  lava 
as  it  came  out  from  the  opening  on  the  top  of  Jorullo, 
flowed  in  all  directions  around  the  opening,  thus  building 
up  a  mountain  in  the  form  of  a  flat  lava  cone. 

Perhaps  one  of  the  reasons  Humboldt  had  for  believ- 
ing the  entire  elevation  of  Jorullo  to  be  due  to  the  forma- 
tion of  a  huge  bladder  was  the  fact  that  the  plain  on  which 
the  cone  is  situated,  when  struck,  gave  out  a  sound  as 
though  there  was  a  vast  hollow  space  below  it.  This  was 
especially  the  case  when  the  hoofs  of  the  horses  driven 
over  its  surface  produced  sounds  as  though  they  were 
moving  over  the  summit  of  a  hollow  dome-like  space  be- 
low. But,  as  Lyell  points  out,  this  was  probably  only  due 
to  the  fact  that  the  materials  forming  the  cone  were 
very  light  and  porous. 

According  to  Burkhardt,  a  German   mining  engineer 


134         VOLCANOES  AND  EARTHQUAKES 

who  visited  Jorullo  in  1827,  there  appears  to  have  been 
no  other  eruptions  of  the  volcano  since  the  time  of  Hum- 
boldt's  visit.  Mr.  Burkhardt  descended  to  the  bottom 
of  the  crater  and  observed  that  small  quantities  of  sul- 
phurous vapors  were  still  escaping.  The  small  cones  or 
hornitos,  however,  on  the  slopes  had  entirely  ceased  emit- 
ting steam.  It  appeared,  too,  that  the  twenty-four  years 
that  had  passed  since  the  time  of  Humboldt's  visit,  the 
rich  soil  of  the  surrounding  country  had  permitted  the  suc- 
cessful cultivation  of  some  crops  of  sugar  cane  and  in- 
digo. 

Russell  appears  to  doubt  the  reliability  of  the  informa- 
tion obtained  by  Humboldt  concerning  Jorullo.  He 
suggests  that  a  poetical  account  by  the  Jesuit  missionary 
from  whom  Humboldt  obtained  much  of  his  information 
was  not  apt  to  possess  marked  scientific  accuracy.  While, 
however,  this  may  be  true,  yet  to  a  certain  extent  it 
seems  entirely  probable  that  the  principal  facts  were  as 
above  given.  The  following  account  as  given  by  Hum- 
boldt, is  taken  from  a  translation  made  in  the  early  part 
of  1800: 

"The  affrighted  inhabitants  fled  to  the  mountains  of 
Aguasarco.  A  tract  of  ground  from  three  to  four  square 
miles  in  extent,  which  goes  by  the  name  of  Malpays,  rose 
up  in  the  shape  of  a  bladder.  The  bounds  of  this  con- 
vulsion are  still  distinguishable  in  the  fractural  strata. 
The  Malpays,  near  its  edge,  is  only  twelve  metres  above 
the  old  level  of  the  plain  called  the  Playas  de  Jorullo;  but 
the  convexity  of  the  ground  thus  thrown  up  increases 
progressively  towards  the  centre,  to  an  elevation  of  160 
metres  (524.8  ft.). 

"Those  who  witnessed  this  catastrophe  from  the  top 
of  Aguasarco  assert  that  flames  were  seen  to  issue  forth 
for  an  extent  of  more  than  half  a  square  league,  that  frag- 


JORULLO  135 

ments  of  burning  rocks  were  thrown  up  to  prodigious 
heights,  and  that  through  a  thick  cloud  of  ashes,  illumi- 
nated by  the  volcanic  fire,  the  softened  surface  of  the  earth 
was  seen  to  swell  up  like  an  agitated  sea.  The  rivers  of 
Cuitamba  and  San  Pedro  precipitated  themselves  into 
the  burning  chasms.  The  decomposition  of  the  water 
contributed  to  invigorate  the  flames,  which  were  dis- 
tinguishable at  the  city  of  Pascuaro,  though  situated  on 
very  extensive  table-land  1,400  metres  (4,592  ft.)  elevated 
above  the  plains  of  Las  Playas  de  Jorullo.  Eruptions  of 
mud,  and  especially  of  strata  of  clay  enveloping  balls  of 
decomposed  basalt  in  concentrical  layers,  appeared  to 
indicate  that  subterranean  water  had  no  small  share  in 
producing  this  extraordinary  revolution.  Thousands  of 
small  cones,  from  two  to  three  metres  in  height,  called 
by  the  indigenes  ovens,  issued  forth  from  the  Mai- 
pays.  .  .  . 

"  In  the  midst  of  the  ovens,  six  large  masses,  elevated 
from  400  to  500  metres  each  above  the  old  level  of  the 
plain,  sprung  up  from  a  chasm,  of  which  the  direction  is 
from  N.  N.  E.  to  the  S.  S.  E.  This  is  the  phenomenon  of 
the  Montenovo  of  Naples,  several  times  repeated  in  a 
range  of  volcanic  hills.  The  most  elevated  of  these  enor- 
mous masses,  which  bears  some  resemblance  to  the  puys 
de  1'Auvergne,  is  the  great  Volcan  de  Jorullo.  It  is  con- 
tinually burning,  and  has  thrown  up  from  the  north 
side  an  immense  quantity  of  scorified  and  basaltic  lavas 
containing  fragments  of  primitive  rocks.  These  great 
eruptions  of  the  central  volcano  continued  till  the  month 
of  February,  1760.  In  the  following  years  they  became 
gradually  less  frequent.  .  .  .  The  roofs  of  the  houses  of 
Queretaro  were  then  covered  with  ashes  at  a  distance  of 
more  than  forty-eight  leagues  in  a  straight  line  from 
the  scene  of  the  explosion.  Although  the  subterranean 


136         VOLCANOES  AND  EARTHQUAKES 

fire  now  appears  far  from  violent,  and  the  Malpays  and 
the  great  volcano  begin  to  be  covered  with  vegetation,  we 
nevertheless  found  the  ambient  air  heated  to  such  a 
degree  by  the  action  of  the  small  ovens,  that  the  ther- 
mometer at  a  great  distance  from  the  surface  and  in  the 
shade  rose  as  high  as  43°  C."  (109°  4'  F.). 


CHAPTER  XIV 

MID-OCEAN    VOLCANIC  ISLANDS 

Besides  the  volcanoes  we  have  already  described,  there 
are  many  others  situated  in  mid- ocean  far  from  any 
continent.  A  brief  description  will  be  given  of  a  few  of 
these. 

All  the  three  great  central  oceans,  the  Pacific,  the  At- 
lantic, and  the  Indian,  contain  numerous  volcanic  islands, 
some  of  which  rise  many  thousands  of  feet  above  the 
general  level. 

We  will  begin  with  a  description  of  some  of  the  more 
important  volcanic  islands  of  the  Pacific.  It  was  first 
pointed  out  by  Kotzebue,  and  afterwards  by  Darwin, 
that  all  the  islands  of  the  Pacific  Ocean  can  be  divided 
into  two  great  classes,  the  high  islands  and  the  low  islands. 
All  the  high  islands  are  of  volcanic  origin,  while  the  low 
islands  are  of  coral  formation.  It  is  the  opinion  of  Dana, 
who  has  made  a  careful  study  of  coral  formations,  espe- 
cially in  the  Pacific,  that  in  all  probability  even  the  low 
islands  of  the  Pacific  were  originally  volcanic,  and  that  the 
deposits  of  coral  had  been  made  along  their  shores  after 
their  volcanoes  had  become  extinct. 

The  islands  of  the  Pacific,  like  the  shores  of  the  conti- 
nents and  most  of  their  mountain  ranges,  extend  in  two 
great  lines  of  trend,  or  general  direction,  which  intersect 
each  other  nearly  at  right  angles.  These  lines  extend 
from  the  southeast  to  the  northwest,  and  from  the  north- 
east to  the  southwest  respectively,  those  extending  in 
[137] 


138         VOLCANOES  AND  EARTHQUAKES 

a  general  direction  from  southeast  to  northwest  being 
the  most  common  in  the  Pacific. 

Now,  perhaps,  the  greatest  number  of  the  earth's 
volcanoes  are  arranged  along  fissures,  or  cracks  in  the 
earth's  crust.  The  craters  are  situated  along  the  cracks, 
the  openings  being  kept  clear  at  the  crater,  and  gradually 
closing  elsewhere,  probably  by  pressure.  In  other  words, 
most  of  the  volcanoes  follow  one  another  along  more  or 
less  straight  lines.  For  example,  in  the  western  part  of 
South  America  they  follow  the  Andes  Mountains.  A 
similar  arrangement  exists  in  the  volcanoes  of  Central 
America,  Mexico,  and  the  United  States.  Now,  this  is 
especially  true  of  mid-ocean  volcanoes  of  the  Pacific  which 
lie  along  lines  extending  from  southeast  to  northwest,  or 
from  northeast  to  southwest,  though  mainly  along  the 
former. 

Some  of  the  volcanic  islands  of  the  Pacific  have  already 
been  described  or  referred  to,  as,  for  example,  the  Aleu- 
tian Islands,  which  stretch  in  a  curved  line  from  the  south- 
western extremity  of  the  peninsula  of  Alaska  to  Kamts- 
chatka  on  the  coast  of  Asia.  We  have  already  described 
the  island  of  Hawaii,  the  great  volcanoes  of  the  Sandwich 
Islands  chain,  and  besides  these  there  are  in  the  North 
Pacific  the  Ladrone  Islands,  lying  east  of  the  Philippines. 

Some  of  the  principal  remaining  islands  are:  the  Fejee 
Islands,  which  are  volcanic,  with  numerous  hot  springs 
and  craters.  The  Friendly  Islands,  with  the  peak  of 
Tafua,  2,138  feet  high,  an  active  volcano  with  a  large 
crater  always  burning,  and  two  other  volcanoes,  Apia, 
and  Upala.  Tahiti,  to  the  east,  is  at  present  extinct.  One 
of  its  mountains,  Orobena,  said  to  be  10,000  feet  high,  has 
a  crater  on  its  summit.  The  Marquesas,  still  further  to 
the  east,  are  also  volcanic.  All  of  these  islands  lie  gener- 
ally in  the  lines  of  the  northeast  trend. 


MID-OCEAN  VOLCANIC  ISLANDS  139 

The  Tongan  or  New  Zealand  Island  chain  extends  in 
the  direction  of  the  northeast  trend.  This,  as  you  will 
see,  is  the  direction  in  which  the  two  islands  of  New 
Zealand  extend.  The  Tongan  Island  chain  is  continued 
to  the  south  through  Auckland  and  the  Macquaire  Islands 
to  58°  S.  Towards  the  north,  in  almost  the  same  line, 
are  the  Kermadec  Islands  near  30°  S. 

There  are  several  active  volcanoes  in  New  Zealand. 
An  explosive  eruption  of  Tarawera,  in  New  Zealand,  in 
1883,  continued  for  several  days,  and  was  followed,  three 
days  afterwards,  by  an  outburst  in  an  active  volcano  in 
the  Bay  of  Plenty,  and  two  months  afterwards,  by  a 
violent  outburst  in  a  volcano  on  the  island  of  Ninafou  in 
the  Tongan  Islands. 

Coming  now  to  the  Atlantic  Ocean  we  find  a  number  of 
volcanic  mountains  in  the  deep  waters  near  mid-ocean. 
The  principal  of  these,  besides  Iceland,  are  the  Azores, 
the  Canaries,  Cape  Verde  Islands,  Ascension  Island,  St. 
Helena  Island,  and  Tristan  d'Acunha.  The  Peak  of  Pico, 
in  the  Azores,  rises  to  a  height  of  7,016  feet.  The  Peak  of 
Teneriffe,  in  the  Canaries,  reaches  the  height  of  12,225  feet. 
Teneriffe  is  a  snow-capped  mountain.  It  has  a  cone  on 
its  summit  with  precipitous  walls  like  Vesuvius.  Sul- 
phurous vapors  are  continually  formed  at  its  summit, 
but  no  flames  can  be  seen. 

In  the  Cape  Verde  Islands  is  to  be  found  the  active 
volcanic  mountain  of  Fuego,  rising  7,000  feet  above  the 
sea.  It  has  a  central  cone  that  has  been  broken  down 
on  one  side  like  that  of  Somma  on  Vesuvius.  Fuego  was 
in  eruption  in  1785,  and  also  in  1799. 

Ascension  Island,  south  of  the  equator,  is  formed  en- 
tirely of  volcanic  materials.  This  island  rises  from  an 
apparently  granite  floor  on  the  bed  of  the  ocean,  in  water 
12,000  feet  deep. 


140         VOLCANOES  AND  EARTHQUAKES 

St.  Helena  lies  further  to  the  south.  It  is  an  extinct 
volcano,  and  has  the  remains  of  a  crater  on  its  summit 
with  lava  dikes  in  various  parts  of  the  island. 

Tristan  d'Acunha  is  an  isolated  mountain  that  lies  in 
the  South  Atlantic,  south  of  St.  Helena,  1,500  miles 
from  Africa,  the  nearest  land.  It  is  an  extinct  volcano  that 
rises  from  a  depth  of  12,150  feet  to  a  height  of  7,000  feet 
above  the  sea.  It  has  a  truncated  cone  on  its  summit 
and  a  lake  of  pure  water  in  its  old  crater. 

There  are  only  a  few  volcanic  islands  in  the  Indian 
Ocean.  Kerguelen  Island  lies  in  the  southern  waters. 
St.  Paul  and  Amsterdam  to  the  north,  lying  near  40°  S. 
lat.,  as  well  as  the  Crozet  Islands,  are  extinct  volcanoes. 

In  the  Arctic  Ocean  is  the  volcanic  island  of  Jan  Mayen. 
In  the  Antarctic  Ocean,  as  far  as  is  known,  there  are  only 
two  volcanoes,  Mt.  Erebus  and  Mt.  Terror.  Mt.  Erebus, 
12,400  feet  high,  is  an  active  volcano.  Mt.  Terror,  10,990 
feet  high,  is  an  extinct  volcano. 


CHAPTER  XV 

SUBMARINE  VOLCANOES 

A  submarine  volcano  is  a  volcano  that  erupts  on  the 
bed  of  the  ocean  with  its  crater  covered  by  the  waters. 
Many  of  the  great  volcanic  mountains  of  the  world  began 
as  submarine  volcanoes.  A  crater  first  opened  on  the 
floor  of  the  ocean,  and  lava  escaping,  was  heaped  up 
around  the  opening,  until  it  emerged  above  the  surface 
as  an  island.  As  we  have  seen,  the  island  of  Iceland  is 
believed  to  have  begun  in  this  way.  Such,  too,  in  all 
probability,  was  the  origin  of  Hawaii,  Vesuvius,  Etna, 
and  Santorin. 

But  besides  the  volcanic  mountains  that  were  thrown 
up  during  the  geological  past,  there  are  others  that  have 
been  called  into  existence  while  man  has  been  living  on 
the  earth.  We  will  now  describe  a  few  islands  that  have 
been  formed  in  this  manner  by  submarine  volcanic  erup- 
tions. 

That  volcanic  eruptions,  or  at  least  something  that 
greatly  resembles  eruptions,  occur  on  the  bed  of  the  ocean 
too  far  below  the  surface  to  permit  them  to  be  directly 
seen  from  above,  has  been  shown  in  a  number  of  cases 
where  the  captains  of  vessels  have  reported  that  in  certain 
parts  of  the  ocean,  jets  of  water,  or  steam,  and  pillars 
of  flame  have  been  seen  rising  to  great  heights  from  the 
surface  of  the  water,  and  that  in  certain  regions  sulphur- 
ous smoke  has  also  been  seen.  During  such  occurrences, 
the  water  is  agitated,  as  if  it  were  being  violently  boiled. 
[141] 


142          VOLCANOES  AND  EARTHQUAKES 

Moreover,  these  parts  of  the  ocean  are  shaken  by  severe 
earthquake  shocks. 

Another  evidence  of  submarine  volcanic  eruptions  is 
to  be  found  in  great  quantities  of  ashes,  scoriae,  or  pumice 
stone,  that  are  seen  spread  out  over  the  surface  of  the 
ocean  after  the  commotions  referred  to  in  the  preceding 
paragraph.  Still  another  proof  is  that  parts  of  the  ocean 
whose  waters  were  previously  very  deep  are  found  to  have 
suddenly  shoaled. 

Of  course,  the  best  proof  is  the  appearance  of  rocky 
reefs  or  small  islands  thrown  up  above  the  surface  of  the 
water,  especially  where  volcanic  cones  appear.  While 
in  many  cases  the  new  islands  thus  thrown  up  are  sub- 
sequently washed  away  by  the  waves,  yet  some  have 
continued  above  the  water. 

One  of  the  most  noted  instances  of  the  formation  of  an 
island  by  a  submarine  volcano  was  Sabrina,  which  was 
thrown  up  in  1811,  in  the  Atlantic  Ocean,  off  the  shores 
of  St.  Michael  in  the  Azores  Islands.  Sabrina  had  a  cone 
that  was  300  feet  in  height.  It  did  not  long  remain  above 
the  waters,  however,  being  soon  washed  away  by  the 
waves.  It  is  interesting  to  note  that  in  the  same  part  of 
the  ocean  where  Sabrina  appeared,  other  islands  have 
appeared  and  disappeared,  at  times  long  before  1811; 
that  is,  during  the  year  1691,  as  well  as  during  1720. 

Another  instance  of  a  submarine  island  is  Graham's 
Island,  that  was  thrown  up  in  1831,  in  the  Mediterranean 
Sea,  between  the  west  coast  of  Sicily  and  the  nearest  part 
of  Africa,  on  which  ancient  Carthage  was  situated.  The 
part  of  the  sea  where  the  island  was  thrown  up  had  pre- 
viously a  depth  of  600  feet. 

The  general  appearance  of  Graham's  Island  is  repre- 
sented in  Fig.  22. 

Graham's  Island  was  formed  by  accumulations  of  loose 


SUBMARINE  VOLCANOES 


143 


scoria  and  cinders,  together  with  blocks  of  lava  and  frag- 
ments of  limestone.  It  reached  a  height  of  200  feet  above 
the  water,  but  only  remained  above  the  surface  for  a  few 
months,  when  it  was  washed  away,  leaving  a  submarine 
bank  some  twelve  miles  in  width,  that  was  covered  by 
water  of  about  150  feet,  but  which,  however,  increased 


FIG.  22.     GRAHAM'S  ISLAND — A  RECENT  VOLCANIC  ISLAND 

rapidly  in  depth  towards  the  edge  until  depths  of  from 
1,200  to  2,000  feet  were  reached. 

According  to  Lyell,  on  the  28th  of  June,  1831,  before 
Graham's  Island  appeared,  a  ship  passing  over  this  por- 
tion of  the  sea  felt  severe  earthquake  shocks.  On  July 


144         VOLCANOES  AND  EARTHQUAKES 

10th  of  the  same  year,  the  captain  of  a  vessel  from  Sicily 
reported  that  as  he  passed  near  this  part  of  the  Mediter- 
ranean, a  column  of  water,  800  yards  in  circumference,  was 
seen  to  rise  from  the  sea  to  a  height  of  sixty  feet,  and  that 
afterwards  a  column  of  steam  rising  to  a  height  of  1,800 
feet  was  seen  in  the  same  place.  On  again  passing  the 
same  region  on  July  18th,  this  captain  found  a  small 
island  about  twelve  feet  in  height,  with  a  crater  in  its 
centre,  that  was  throwing  out  volcanic  materials,  together 
with  immense  masses  of  vapor. 

The  island  thus  formed  grew  rapidly,  both  in  size  and 
height.  When  visited  at  the  end  of  July,  it  had  attained 
a  height  of  from  fifty  to  ninety  feet,  and  was  three- 
quarters  of  a  mile  in  circumference.  By  August  4th,  it 
had  reached  a  height  of  200  feet,  and  was  then  some  three 
miles  in  circumference.  From  this  time,  however,  the 
island  began  to  decrease  in  size,  as  the  waves  began  to 
wash  it  away.  By  August  25th,  it  was  only  two  miles 
in  circumference.  On  September  3d,  it  had  decreased  to 
three-fifths  of  a  mile  in  circumference,  and  continued  to 
decrease  until  it  entirely  disappeared,  so  that  in  the  year 
1832,  there  were,  according  to  measurements,  some  150 
feet  of  water  over  its  former  site. 

The  Mediterranean  Sea  between  Sicily  and  Greece  is 
also  especially  liable  to  submarine  activity.  New  islands 
appear  and  disappear  so  frequently  that  in  this  region 
they  are  almost  regarded  as  common  phenomena. 

There  are  many  other  parts  of  the  ocean  where  sub- 
marine volcanic  eruptions  are  common.  This  is  especially 
the  case  in  the  narrowest  part  of  the  Atlantic  Ocean  be- 
tween Africa  and  South  America.  Here  there  is  a  region 
situated  partly  above  the  equator,  though  for  the  greater 
part  south  of  the  equator,  frequently  visited  by  submarine 
eruptions,  that  are  accompanied  by  earthquakes,  by  the 


SUBMARINE  VOLCANOES  145 

agitation  of  the  water,  by  the  appearance  of  floating 
masses  of  ashes  and  scorise,  as  well  as  by  columns  of  steam 
or  smoke.  Floating  masses  of  ashes  and  scoriae  some- 
times occur  so  thick  as  to  retard  the  progress  of  vessels. 

But  what  forms,  perhaps,  one  of  the  best  instances  of 
a  large  island  formed  by  submarine  eruptions  during 
historical  times,  is  Bogosloff  Island  in  Behring  Sea,  some 
forty  miles  west  of  Unalaska  Island.  This  island,  the 
position  of  which  is  seen  on  the  accompanying  map,  is 
known  to  the  Russians  as  loanna  Bogoslova,  or  St.  John 
the  Theologian.  It  is  situated  in  lat.  53°  58'  N.,  long.  168° 
west.  It  is  said  that  during  the  year  1795,  some  of  the 
natives  of  Unalaska  Island  saw  what  they  thought  was 
a  fog  in  the  neighborhood  of  a  small  rock,  which  they  had 
known  for  a  long  time  to  project  above  the  sea  in  these 
waters.  This  rock  was  marked  on  some  Russian  chart 
dated  1768-69.  It  was  seen  by  Captain  Cooke,  in  1778, 
and  was  named  by  him  Ship  Rock. 

But  it  was  not  a  fog  that  the  Unalaskans  had  seen  in 
the  neighborhood  of  Ship  Rock;  for,  to  their  great  sur- 
prise, the  fog  continued  in  sight  although  everywhere  else 
the  air  was  quite  clear.  Of  course,  this  was  a  great  mys- 
tery to  the  people.  During  the  spring  of  1796,  one  of  them, 
who  possessed  either  greater  curiosity  than  the  rest,  or 
greater  courage,  or  both,  visited  the  rock.  He  returned, 
telling  the  strange  story  that  all  the  ocean  around  the 
rock  was  boiling,  and  that  the  mist  or  fog  was  caused  by 
the  rising  steam.  What  was  taking  place  was  a  submarine 
eruption.  During  May,  1796,  sufficient  matter  had  been 
brought  up  from  below  to  increase  greatly  the  area  of 
the  small  rock.  , 

During  later  years  several  attempts  have  been  made 
to  visit  Bogosloff  Island.  For  example,  the  island  was 
visited  during  1872  and  1873,  when  it  was  found  to  have 


146         VOLCANOES  AND  EARTHQUAKES 


SUBMARINE  VOLCANOES  147 

increased  in  height  to  850  feet.  But  no  appearance  of 
any  volcanic  crater  was  to  be  seen. 

During  October,  1883,  a  great  volcanic  eruption  oc- 
curred there.  Considerable  changes  were  produced  in  its 
shape,  as  well  as  in  the  depth  of  the  surrounding  water. 
During  this  eruption,  clouds  of  steam  completely  hid  the 
island.  Great  quantities  of  ashes  obscured  the  light  of 
the  sun.  After  the  eruption,  a  new  island  was  thrown  up 
near  the  old  one,  in  a  place  where  the  water  had  previously 
been  deep  enough  for  the  ready  passage  of  ships.  The 
new  island  was  about  half  a  mile  from  the  old  one.  It  was 
conical  in  form,  from  500  to  800  feet  in  height,  and  about 
three-quarters  of  a  mile  in  diameter. 

The  new  island  was  visited  in  1884  by  the  U.  S.  Revenue 
Marine  Steamer  Corwin.  Lieutenant  Cartwell,  who 
visited  the  island  at  this  time,  described  it  as  follows: 

"The  sides  of  New  Bogosloff  rise  with  a  gentle  slope  to 
the  crater.  The  ascent  at  first  appears  easy,  but  a  thin 
layer  of  ashes,  formed  into  a  crust  by  the  action  of  rain 
and  moisture,  is  not  strong  enough  to  sustain  a  man's 
weight.  At  every  step  my  feet  crushed  through  the  outer 
covering  and  I  sank  at  first  ankle-deep  and  later  on  knee- 
deep  into  a  soft,  almost  impalpable  dust  which  arose  in 
clouds  and  nearly  suffocated  me.  As  the  summit  was 
reached,  the  heat  of  the  ashes  become  almost  unbearable, 
and  I  was  forced  to  continue  the  ascent  by  picking  my  way 
over  rocks  whose  surfaces  being  exposed  to  the  air,  were 
somewhat  cooled  and  afforded  a  more  secure  foothold. 

"On  all  sides  of  the  cone  there  are  openings  through 
which  steam  escaped  with  more  or  less  energy.  I  observed 
from  some  vents  the  steam  was  emitted  at  regular  in- 
tervals, while  from  others  it  issued  with  no  perceptible 
intermission.  Around  each  vent  there  was  a  thick  deposit 
of  sulphur,  which  gave  off  suffocating  vapors." 


CHAPTER  XVI 

DISTRIBUTION    OF    THE    EARTH'S    VOLCANOES 


Having  now  considered  at  some  length  the  principal 
volcanoes  of  the  earth,  and  endeavored  to  obtain  some 
idea  of  the  many  wonders  they  exhibit,  especially  as  re- 
gards the  vast  quantities  of  material  they  bring  from  the 
inside  of  the  earth,  as  well  as  the  great  force  with  which 
they  sometimes  throw  these  materials  out  of  their  craters, 
it  will  be  well  to  point  out  where  such  volcanoes  are  to  be 
found. 

It  may  have  seemed  to  you,  when  you  have  carefully 
followed  what  has  been  said  about  the  earth's  volcanoes, 
that  they  are  to  be  found  pretty  nearly  everywhere,  at 
least  so  far  as  latitude  is  concerned;  and  in  this  supposi- 
tion you  are  correct;  for  there  are  volcanoes  in  the  Arctic 
Ocean,  as  in  the  volcanic  island  of  Jan  Mayen  between 
Iceland  and  Spitzbergen,  there  are  Mt.  Erebus  and  Mt. 
Terror  in  the  Antarctic  Ocean,  besides  very  numerous 
volcanoes  in  the  Atlantic,  Pacific,  and  Indian  Oceans,  and 
their  shores  in  both  the  temperate  and  the  torrid  zones. 

There  is,  however,  one  thing  that  you  have  probably 
especially  noticed  and  that  is  that  volcanoes  are  seldom 
found  at  very  great  distances  from  the  ocean,  except  on 
some  of  its  arms  or  seas,  such  as  the  Mediterranean  Sea. 
I  do  not  mean  by  this  that  all  the  earth's  volcanoes  are 
either  situated  directly  on  the  coast  of  the  continents  or 
on  islands,  since,  in  such  a  large  body  as  the  earth,  a  dis- 
tance of  a  few  hundred  miles  from  the  ocean  is  hardly 
[148] 


DISTRIBUTION  OF  EARTH'S  VOLCANOES  149 

to  be  regarded  as  being  very  far  from  it.  But  it  is  true  that 
all  the  earth's  volcanoes  are  either  situated  on  the  coasts 
of  the  continents,  or  on  islands,  and,  moreover,  they  are 
situated  to  a  greater  or  less  extent  along  lines,  which, 
as  we  have  already  pointed  out,  are  believed  to  mark  weak 
portions  of  the  earth's  crust  that  have  been  fissured  or 
fractured. 

In  order  that  you  may  have  some  idea  of  this  dis- 
tribution, I  think  it  will  be  well  to  give  you  a  number  of 
interesting  facts  that  have  been  pointed  out  by  Dana. 
According  to  this  authority,  there  are  something  in  the 
neighborhood  of  300  active  volcanoes  on  the  earth. 
Of  these,  no  less  than  five-sixths,  or  250,  lie  either  on  the 
borders  of  the  Pacific  Ocean,  or  on  some  of  its  many 
islands.  Thirty-nine  either  lie  within  or  on  the  borders 
of  the  Atlantic,  of  which  thirteen  are  in  Iceland,  or  near 
the  Arctic  Circle,  three  in  the  Canaries,  seven  in  the 
Mediterranean  Sea,  six  in  the  Lesser  Antilles,  and  ten  in 
the  Atlantic  Oceanic  Islands.  The  Indian  Ocean  con- 
tains only  a  few  active  volcanoes.  There  are,  however, 
a  much  greater  number  of  extinct  volcanoes,  which  may 
at  any  time  again  become  active. 

The  following  is  the  distribution  of  the  earth's  volcanoes 
as  given  by  Dana.  As  you  will  see,  from  an  inspection 
of  Fig.  24,  all  of  the  regions  of  volcanoes  lie  either  on 
the  borders  of  the  continents,  or  on  islands  in  the  oceans. 
The  districts  are  as  follows: 

1.  Scattered  Over  the  Pacific  Ocean. — This  district  in- 
cludes the  following  active  volcanoes;  i.  e.,  the  Hawaiian 
Islands,  nearly  in  mid-ocean,  almost  directly  below  the 
Tropic  of  Cancer;  in  the  west  central  parts  of  the  South 
Pacific;  in  the  New  Hebrides;  in  the  Friendly  Islands, 
the  Tongan  or  New  Zealand  Islands,  in  the  Santa  Cruz 
Islands,  and  in  the  Ladrones 


150  VOLCANOES  AND  EARTHQUAKES 


DISTRIBUTION  OF  EARTH'S  VOLCANOES   151 

2.  On  the  Borders  of  the  Pacific. — This  district  includes 
the  volcanoes  that  extend  from  the  southern  part  of  South 
America  at  intervals  along  the  Andes  Mountain  range. 
Of  these  there  are  thirty-two  in  Chile,  seven  or  eight  in 
Bolivia  and  Southern  Peru;  about  twenty  in  the  neigh- 
borhood of  Quito.     Further  north  there  are  thirty-nine 
in  Central  America,  and  seven  in  Mexico.     Proceeding 
northwards  through  the  United  States,  there  are  a  num- 
ber of  volcanic  mountains,  generally  extinct,  in  portions 
of  the  Sierra  Nevadas  and  Cascade  Ranges.     Probably 
a  number  of  volcanic   mountains  exist  in  portions  of 
Canada  lying  between  the  northern  boundaries  of  the 
United   States  and  Alaska,  and  a  number  in  Alaska; 
some   twenty-one   volcanic   mountains   in   the  Aleutian 
Islands;  some  fifteen  or  twenty  in  Kamtchatka;  thirteen 
in  the  Kuriles;  some  twenty-five  or  thirty  in  Japan  and 
the  neighboring  islands;  some  fifteen  or  twenty  in  the 
Philippines;  several  along  the  northern  coasts  of  New 
Guinea;    a  number  in  New  Zealand  and  south  of  Cape 
Horn;  the  volcanoes  of  the  Deception  Island  with  its  hot 
springs,  and  also  in  the  South  Shetlands  62°  30'  S. 

3.  In  the  Indian  Ocean. — On  the  western  border  of  the 
Indian  Ocean  there  are  a  few  volcanoes  in  Madagascar; 
in  the  Island  of  Bourbon;  Mauritius;  the  Comoro  Islands; 
and  in  Kerguelen  Land  on  the  south.     There  are  also 
volcanoes  on  the  western  border  of  the  Indian  Ocean 
where  the  lofty  peak  of  Kilima  Ndjro,  18,000  feet,  is 
volcanic. 

4.  Over  the  Seas  that  Separate  the  Northern  and  the 
Southern  Continents  and  in   their  Vicinity. — This  is  an 
especially  active  region  of  volcanoes.     For  the  sake  of 
convenience  the  continents  of  the  world  are  sometimes 
divided  into  three  pairs  or  double  continents;  namely, 
North  and  South  America,  connected  by  the  Isthmus  of 


152          VOLCANOES  AND  EARTHQUAKES 

Panama;  Europe  and  Africa,  connected  by  the  Isthmus  of 
Suez;  and  Australia  and  Asia,  completely  separated  by 
a  sunken  isthmus,  the  summits  of  which  form  the  Sunda 
Island  chain.  In  the  first  of  these  regions  we  have  the 
very  active  group  of  the  West  Indies,  where  there  are  ten 
volcanic  islands.  In  the  second  pair  of  double  conti- 
nents we  have  the  volcanoes  of  the  Mediterranean  and 
Red  Seas,  and  their  borders,  such  as  Sicily,  Vesuvius,  and 
other  parts  of  Italy,  Spain,  Germany,  the  Grecian  Archi- 
pelago, Asia  Minor,  and  extending  eastward  through 
the  Caspian,  Mt.  Ararat,  Demavend,  on  the  south  shores 
of  the  Caspian,  Mt.  Ararat,  and  some  few  others  along 
the  borders  of  the  Red  Sea. 

In  the  East  Indies  we  find  the  most  intense  centre  of 
volcanic  activity  in  the  world.  Here  there  are  some  200 
volcanoes  of  which  there  are  nearly  fifty  in  Java  alone, 
more  than  half  of  which  are  still  active.  There  are 
nearly  as  many  volcanoes  in  Sumatra,  and  many  in  the 
small  islands  near  Borneo,  the  Philippines,  etc. 

5.  On  the  Borders  of  the  Atlantic  and  Elsewhere. — It  is  an 
interesting  fact  that  there  are  no  volcanoes  on  the  eastern 
borders  of  the  Atlantic  north  of  the  West  Indies  Island 
chain.  In  the  South  Atlantic  the  only  volcano  on  the 
borders  is  one  of  the  Cameroons  Mountains.  In  the  At- 
lantic Ocean  we  have  Iceland,  the  Azores,  the  Canaries, 
Cape  Verde,  Ascension,  St.  Helena,  and  Tristan  d'Acunha. 

This  curious  distribution  of  the  volcanoes  of  the  world 
near  the  oceanic  waters  appears  to  be  dependent  rather 
on  the  very  early  shapes  of  the  continents  and  the  ocean 
beds  than  on  their  present  shapes. 


CHAPTER  XVII 

VOLCANOES  OF  THE  GEOLOGICAL  PAST 

The  question  is  often  asked  whether  the  volcanic  erup- 
tions of  the  geological  past  were  not  much  more  violent 
and  destructive  than  the  volcanoes  of  the  present  time. 
Now,  while  this  is  a  matter  that  properly  belongs  to  the 
subject  of  geology,  and  will  be  treated  at  greater  length 
in  the  Wonder  Book  on  Geology,  yet  a  short  mention 
should  be  made  of  it  here. 

It  is  the  opinion  of  Dana  that  while  there  have  been 
volcanoes  during  the  different  geological  ages,  yet  volcanic 
activity  has  increased  through  the  geological  past  until 
the  age  that  immediately  preceded  the  appearance  of  man 
on  the  earth.  He  thinks  there  is  no  reason  for  believing 
that  there  were  any  very  great  volcanic  eruptions  during 
the  earliest  geological  time  known  as  the  Archseic.  Dana 
speaks  as  follows  concerning  this: 

"In  this  connection  it  is  an  instructive  fact  that  in 
eastern  North  America,  at  epochs  when  there  was  the 
greatest  amount  of  friction  and  crushing  .  .  .  those  of 
the  making  of  the  Green  Mountains  and  the  Appalachians 
...  no  volcanoes  were  made,  and  little  took  place  in 
the  way  of  eruptions  through  fissures." 

On  the  other  hand,  Prestwich  seems  inclined  to  think 
that  the  absence  of  well-marked  cones  of  volcanic  material 
in  the  rock  of  the  older  geological  ages  is  not  to  be  regarded 
as  proof  that  no  eruptions  then  took  place,  since  the  very 
great  amount  of  erosion  that  occurred  between  that  time 
[153] 


154         VOLCANOES  AND  EARTHQUAKES 

and  the  Tertiary  Age  before  the  appearance  of  man, 
would,  probably,  have  completely  obliterated  any  cones, 
and  even  the  volcanic  materials  would  have  undergone 
such  changes  as  completely  to  alter  their  general  charac- 
ter. He  agrees,  however,  with  Dana  that,  probably,  the 
most  violent  and  explosive  volcanoes  of  the  geological 
ages  have  been  those  of  the  Tertiary  Age. 

Without,  however,  attempting  anything  more  than  a 
brief  reference  to  the  volcanoes  of  the  geological  past,  it 
may  be  said  that  many  of  the  more  important  of  the  ac- 
tive volcanoes  of  the  earth's  present  time  were  begun  in 
the  Tertiary  Age.  Mt.  Etna,  Vesuvius,  and  Mt.  Hecla 
are  believed  to  have  commenced  at  this  time. 

There  is  an  interesting  region  of  geological  volcanoes 
in  the  neighborhood  of  Auvergne  in  Central  France. 
Here  they  occur  in  three  separate  groups  that  extend  over 
a  high  granite  platform  from  north  to  south  for  a  distance 
of  about  100  miles,  and  from  twenty  to  eighty  miles  from 
east  to  west.  The  eruptions  began  in  the  earlier  portions 
of  the  Tertiary  Age,  and  continued  down  to  the  latter 
periods  of  prehistoric  times.  Some  of  these  volcanic  cra- 
ters remain  to-day  almost  as  unaffected  by  erosion  as  if 
they  had  been  formed  but  recently. 

Other  regions  of  geological  volcanoes  are  to  be  found 
in  parts  of  Spain  near  the  foot  of  the  Pyrenees  Mountains, 
in  parts  of  Italy  and  Germany,  as  well  as  in  regions  in 
the  Caucasus  Mountains. 

In  Asia  Minor  there  exists  a  group  of  almost  thirty 
extinct  volcanoes  in  the  neighborhood  of  the  Gulf  of 
Smyrna.  Both  Little  and  Great  Ararat  contain  volcanic 
cones:  that  in  the  latter  mountain  was  active  during  his- 
torical times.  There  are  also  extensive  volcanic  districts 
in  the  Taurus  Mountains.  In  addition  to  these  there 
are  groups  of  extinct  volcanoes  in  portions  of  Central  Asia. 


VOLCANOES  OF  THE  GEOLOGICAL  PAST    155 

Aden,  on  the  Red  Sea,  is  the  centre  of  an  extensive 
volcanic  district.  Indeed,  on  both  shores  of  the  Red  Sea 
there  are  a  few  volcanoes  that  are  still  active,  while  in 
Sinai,  and  in  the  districts  of  the  south,  there  are  several 
extinct  craters. 

But  it  is  in  the  New  World,  especially  on  the  Pacific 
coast  of  North  America,  that  volcanic  activity  was  es- 
pecially great  during  the  geological  past.  There  is  a 
district  containing  volcanic  rocks  that  extends  through 
various  parts  of  western  North  America,  from  New 
Mexico  and  North  California,  to  Oregon  and  British 
Columbia.  This  district  has  a  width  of  from  eighty  to  200 
miles,  and  a  length  of  not  quite  800  miles.  This  great 
area  of  nearly  150,000  square  miles  is  covered  with  great 
sheets  of  volcanic  rocks  except  where  mountain  ranges 
rise  from  them,  or  where  the  rivers  have  cut  deep  valleys 
through  them.  In  portions  of  California  and  New  Mexico 
these  plateaus  rise  to  heights  of  from  8,000  to  10,000  feet, 
while  in  parts  of  Colorado,  where  they  form  huge  dome- 
like mountains,  they  reach  a  thickness  of  14,000  feet.  In 
Oregon  the  sheet  of  lava  is  2,000  feet  thick,  and,  indeed, 
in  some  places,  is  estimated  to  have  a  depth  of  7,000 
feet. 

In  the  opinion  of  nearly  all  American  geologists  these 
great  lava  flows  in  western  North  America  were  not  of 
the  type  known  as  crater  eruptions,  but  were  what  are 
called  fissure  eruptions.  Some  of  them  are  believed  to 
have  occurred  during  geological  times  as  early  as  the 
Eocene.  Prestwich,  however,  is  of  the  opinion  that  the 
eruptions  of  the  past  in  these  portions  of  the  world  were 
not  confined  to  fissure  eruptions,  but  that  crater  eruptions 
also  occurred;  and  that  it  was  towards  the  close  of  the 
Tertiary  Age  that  crater  eruptions  occurred  with  great 
lava  flows.  Indeed,  as  we  have  seen,  in  portions  of  Utah 


156         VOLCANOES  AND  EARTHQUAKES 

and  the  neighborhood  the  remains  of  true  craters  can 
be  found. 

Besides  the  above  there  are  evidences  of  geological 
volcanoes,  of  still  older  times.  In  portions  of  Deccan,  in 
southern  Hindostan,  there  is  an  immense  plateau  formed 
of  trap  rock,  that  extends  from  east  to  west  for  a  distance 
of  400  miles,  and  from  north  to  south  through  from  700 
to  800  miles.  This  district,  with  an  area  of  almost  200,000 
square  miles,  is  covered  with  a  vast  lava  sheet.  It  was, 
in  the  opinion  of  Prestwich,  from  whom  many  of  the  facts 
of  the  geological  volcanic  eruptions  have  been  obtained, 
probably  still  more  extensive.  The  plateau  of  Deccan 
rises  gradually  from  the  east  to  the  west,  where,  in  some 
parts  of  the  Ghauts  Mountains,  it  reaches  a  height  of  from 
4,000  to  5,000  feet. 

One  of  the  greatest  of  these  prehistoric  volcanoes  of 
Scotland  was  a  volcano  in  the  Isle  of  Mull  in  the  Hebrides. 
This  volcano  was  probably  nearly  thirty  miles  across  at 
its  base,  and  was  from  10,000  to  12,000  feet  high.  It  is 
now  only  3,172  feet  in  height. 

According  to  Judd  the  Island  of  Skye  in  Inverness-shire 
is  the  remains  of  a  volcano  that  was  active  in  Tertiary 
times,  probably  many  millions  of  years  ago.  This  volcano 
was  very  large,  probably  about  thirty  miles  across  at  its 
base,  with  a  height  of  perhaps  as  great  as  12,000  or  15,000 
feet.  Now  there  are  only  left  some  granite  and  other 
similar  rocks  that  form  the  Red  Mountains  and  Coolim 
Hills  of  Skye  that  reach  about  3,000  feet  above  the  sea 
level. 

There  are  many  other  parts  of  the  world  containing 
volcanoes  that  were  active  during  the  geological  past. 
The  above,  however,  is  as  far  as  we  can  describe  such 
volcanoes  in  this  book. 


CHAPTER  XVIII 

LAPLACE'S  NEBULAR  HYPOTHESIS 

LaPlace's  nebular  hypothesis  is  the  name  given  to  an 
ingenious  hypothesis  proposed  by  LaPlace,  a  celebrated 
French  astronomer,  in  an  endeavor  to  explain  how  the 
solar  system  has  been  evolved. 

You  will  notice  that  this  is  called  a  hypothesis  and  not 
a  theory.  The  word  hypothesis  is  properly  applied  to  a 
more  or  less  intelligent  guess  or  assumption,  that  has  been 
made  for  the  purpose  of  trying  to  find  out  in  the  cause  of 
any  natural  phenomenon.  A  theory  is  an  expression  of  a 
physical  truth  based  on  natural  laws  and  principles  that 
have  been  independently  established.  A  theory,  therefore, 
is  much  more  complete  than  a  hypothesis.  A  hypothesis, 
as  Silliman  remarks,  bears  the  same  relation  to  a  theory 
or  law,  that  a  scaffolding  does  to  a  completed  building, 
since  it  forms  a  convenient  means  for  erecting  the  build- 
ing. LaPlace's  work  is  properly  called  a  hypothesis, 
because  it  is  not  to  be  considered  as  any  more  than  a 
means  for  enabling  one  intelligently  to  inquire  into  the 
probable  manner  in  which  the  solar  system  has  reached 
its  present  condition,  by  gradual  steps  or  stages  during 
the  almost  inconceivable  length  of  time  since  its  creation. 

Before  describing  LaPlace's  hypothesis  it  will  be  neces- 
sary to  give  you  some  ideas  concerning  what  is  known  by 
astronomers  as  the  solar  system. 

The  solar  system  consists  of  the  sun,  and  the  eight 
large  bodies  called  planets  that  revolve  around  the  sun. 
[157] 


158         VOLCANOES  AND  EARTHQUAKES 

It  also  includes  a  number  of  moons  or  satellites  revolving 
around  the  planets,  a  number  of  small  bodies,  called 
planetoids  or  asteroids,  together  with  numerous  comets 
and  meteorites.  Besides  these  there  is  probably  a  system 
of  meteoric  bodies  that  are  believed  to  revolve  around 
the  sun,  and  to  produce,  by  the  reflection  of  the  light 
from  their  surfaces,  what  is  known  as  the  zodiacal  light. 

The  principal  bodies  of  the  solar  system  are  the  planets. 
These  constitute  eight  large  bodies  named  in  their  order 
from  the  sun,  beginning  with  the  nearest:  Mercury,  Venus, 
Earth,  Mars,  Jupiter,  Saturn,  Uranus,  and  Neptune. 
The  last  four  planets,  Jupiter,  Saturn,  Uranus,  and  Nep- 
tune are  much  larger  than  the  others,  and  are  therefore 
known  as  the  major  planets  in  order  to  distinguish  them 
from  Mercury,  Venus,  Earth,  and  Mars,  which  are  called 
the  minor  planets.  You  can  remember  the  order  in  which 
the  last  three  planets  come  by  their  initial  letter,  S-aturn, 
U-ranus,  and  N-eptune,  spelling  the  word  SUN,  around 
which  they  all  revolve. 

It  may  be  interesting  to  state  here  that  the  ancients 
knew  of  seven  only  of  these  planets.  Since,  as  they 
asserted,  there  were  only  seven  days  in  the  week,  and 
seven  openings  into  the  head;  i.  e.,  two  for  the  eyes,  two 
for  the  nostrils,  two  for  the  ears,  and  one  for  the  mouth, 
it  was  natural  that  there  should  be  but  seven  planets. 
During  later  years,  however,  an  eighth  planet  was  dis- 
covered and  named  Neptune.  It  would  be  interesting 
to  explain  to  you  how  the  position  of  this  planet  was 
reasoned  out  by  mathematical  calculations,  that  is,  in 
other  words,  how,  as  a  result  of  such  calculations,  an 
astronomer  was  told  that  if  he  would  point  his  telescope 
to  a  certain  part  of  the  heavens  he  would  discover  a  new 
planet.  He  did  this  and  located  the  planet  Neptune. 
However  interesting  this  story  may  be  it  belongs  properly 


LAPLACE'S  NEBULAR  HYPOTHESIS       159 

to  astronomy,  and  will  be  described  in  full  in  the  Wonder 
Book  of  Astronomy. 

In  the  opinion  of  some  astronomers  it  is  quite  probable 
that  a  ninth  planet  will  be  found  far  beyond  the  orbit 
of  Neptune.  There  may  also  be  some  additional  planets 
discovered  between  Mercury  and  the  Sun. 

Besides  the  eight  known  planets  there  exist,  somewhere 
between  the  orbits  of  Mars  and  Jupiter,  many  smaller 
planets  called  asteroids,  or  minor  planets.  A  long  time 
ago  it  was  pointed  out  by  Bode  that  a  curious  relation 
exists  between  the  distances  of  the  planets  from  the  sun. 
This  relation  or  law  is  generally  known,  after  the  name 
of  the  astronomer  who  first  called  attention  to  it,  as  Bode's 
Law.  No  reason  has  been  discovered  for  this  arrangement 
of  the  planets,  so  that  Bode's  Law  may  be  regarded  as 
empirical.  It  may,  however,  be  mentioned  here  that 
the  distances  of  all  the  planets  from  the  sun  agrees  with 
the  law  very  closely,  with  the  single  exception  of  Neptune, 
which  is  quite  at  variance  with  the  law. 

It  was  noticed  at  an  early  date,  that  a  gap  existed  be- 
tween Mars  and  Jupiter,  so  that  astronomers  began  to 
believe  that  there  was  probably  a  missing  planet  in  that 
space,  and  this  belief  was  greatly  strengthened  when 
Neptune  was  discovered  in  1781.  Without  going  any 
further  into  this  story  in  this  book,  it  may  be  said  that  it 
is  the  general  opinion  of  astronomers  that  the  planetoids 
or  asteroids  were  formed  possibly  from  the  fragments  of 
the  missing  planet,  or,  more  probably,  from  the  breaking 
up  of  some  of  the  outer  rings  on  the  planet  Mars. 

The  distances  of  the  planets  from  the  central  sun  vary 
from  the  nearest  planet,  Mercury,  which  is  about  36,000,000 
miles  from  the  sun,  to  the  furthest,  or  Neptune,  which  is 
2,766,000,000  miles  from  the  sun. 

All  the   major   planets  have  a  single  moon,  or  more, 


160         VOLCANOES  AND  EARTHQUAKES 

revolving  around  them.  For  example,  Jupiter  has  four 
moons;  Uranus,  six;  Saturn,  eight;  Neptune,  one.  As  to 
the  minor  planets,  Mars  has  two  moons;  and,  as  far  as  is 
known,  neither  Mercury  or  Venus  has  a  moon.  Our  earth 
has  one  moon,  but,  as  we  shall  afterwards  see,  this  is  not 
to  be  regarded  as  a  moon  or  satellite  of  the  earth,  but 
rather  as  a  twin  planet  to  the  earth. 

LaPlace's  nebular  hypothesis  was  proposed  by  LaPlace 
during  the  year  1796.  While  there  are  many  objections 
that  can  be  brought  against  it,  since  it  fails  to  account 
for  all  of  the  phenomena  of  the  solar  system,  yet  it  is  a 
significant  fact  now,  in  the  year  1907,  nearly  a  century 
and  a  quarter  after  the  hypothesis  was  first  announced, 
that  although  modified  in  many  respects,  there  has  not 
been  any  hypothesis  proposed  to  entirely  replace  it. 

While  the  nebular  hypothesis  of  LaPlace  is  necessarily 
a  matter  that  belongs  to  astronomy,  yet  it  will  be  advis- 
able to  consider  it  here,  since  it  explains  the  source  of 
the  original  heat  of  both  the  earth  and  the  moon,  which 
we  believe  is  the  true  cause  of  volcanoes. 

In  his  nebular  hypothesis,  LaPlace  assumes  that  all 
the  materials  of  which  the  solar  system  is  formed,  were 
originally  scattered  throughout  space  in  the  shape  of  an 
exceedingly  rare  form  of  matter  known  as  nebulous 
matter.  He  points  out  that  if  it  be  granted  that  this 
medium  began  to  accumulate  around  a  common  centre, 
so  as  to  form  a  huge  globe  or  sphere,  and  if  a  motion  of 
rotation  on  its  axis  from  west  to  east  were  given  to  this 
sphere  that,  on  strictly  mechanical  principles,  a  system 
of  heavenly  bodies  corresponding  to  the  solar  system 
might  have  been  evolved.  Let  us,  therefore,  try  to  under- 
stand how  this  might  have  been  brought  about. 

The  nebulous  matter  that  LaPlace  assumed  originally 
constituted  all  the  matter  in  the  solar  system,  was  highly 


LAPLACE'S  NEBULAR  HYPOTHESIS       161 

heated  gaseous  matter.  In  other  words,  it  consisted  of 
ordinary  matter  raised  to  a  very  high  temperature; 
LaPlace  thought  at  a  temperature  very  much  hotter  than 
that  of  the  sun. 

As  this  great  mass  of  matter  commenced  to  cool,  it 
began  to  collect  around  a  centre  and  slowly  rotate.  Its 
contraction  or  shrinkage,  while  cooling,  must  have  caused 
an  increase  in  the  speed  with  which  it  spun  around  or 
rotated  on  its  axis.  At  first  it  spun  but  sluggishly,  but  as 
it  cooled  and  began  to  shrink  this  rate  of  rotation  began 
slowly  to  increase. 

Now  you  must  bear  in  mind  that  the  huge  rotating 
mass,  as  imagined  by  LaPlace,  was  very  many  times 
larger  than  the  size  of  our  present  sun.  Indeed,  instead 
of  having  a  diameter  of  only  866,500  miles,  its  temperature 
was  so  high  that  the  nebulous  matter  of  which  it  was 
composed  had  expanded  it  so  much  that  it  extended  far 
beyond  the  orbit  of  Neptune,  or  had  a  diameter  twice  as 
great  as  2,766,000,000  miles. 

As  the  huge  mass  continued  to  shrink  or  contract,  its 
rotation  began  to  gradually  increase  until  at  last  its  cen- 
trifugal force  was  sufficiently  great  to  cause  it  to  bulge 
out  at  the  equator,  so  as  at  last  to  separate  a  ring  of 
gaseous  matter.  This  ring  was  left  behind  by  the  sun,  as 
it  continued  cooling,  and  formed  the  first  planet  that  was 
born  into  the  solar  system.  The  ring  might  have  con- 
tinued to  revolve  around  the  sun  for  a  time,  and  would,  of 
course,  revolve  in  the  same  direction  as  that  in  which  the 
sun  was  rotating,  that  is,  from  west  to  east.  Eventually, 
however,  it  broke  up  into  smaller  fragments,  that  after- 
wards collected  in  a  single  body,  and,  assuming  a  globe- 
like  shape  of  the  planet,  formed  the  planet  Neptune. 
Necessarily,  too,  the  planet  so  formed  not  only  would 
revolve  in  its  orbit  from  west  to  east  in  the  same  direction 
K 


162         VOLCANOES  AND  EARTHQUAKES 

in  which  the  sun  was  revolving  on  its  axis,  but  would  also 
rotate  or  spin  on  its  axis  in  the  same  direction. 

After,  in  this  way,  throwing  off  the  first  planet,  the 
central  sun  continued  to  cool  and  grow  smaller,  until  the 
increase  in  the  rate  of  its  rotation  was  again  such  as  to 
permit  its  centrifugal  force  to  form  a  second  ring  around 
its  equator,  which  being  left  as  the  sun  continued  to 
contract,  gave  rise  to  another  planet,  or  to  Uranus,  and 
so  on  until  the  four  major  planets  and  the  four  minor 
planets  were  born. 

According  to  this  hypothesis,  the  planet  that  was  first 
born  was  the  planet  that  is  farthest  from  the  sun,  that 
is,  Neptune,  and  the  planet  last  born  must  have  been 
the  nearest  planet,  Mercury. 

But  while  all  this  planet  forming  was  going  on,  the 
separate  planets  also  continued  to  shrink,  and,  therefore, 
began  to  rotate  more  rapidly  on  their  axes.  Under  the 
influence  of  the  centrifugal  force,  ring-like  masses  began 
to  form  around  their  equators,  and  these  masses  left  by 
the  planet  constituted  their  moons  or  satellites.  As  you 
can  see,  according  to  this  hypothesis,  just  as  the  planets 
would  all  revolve  in  their  orbits  from  west  to  east,  and 
rotate  on  their  axes  in  the  same  direction  as  the  sun,  so, 
too,  the  moons  or  satellites  of  the  planets  would  also 
rotate  on  their  axes,  from  east  to  west,  and  revolve  in  their 
orbits  in  the  same  direction. 

In  order  to  show  the  extent  to  which  LaPlace's  nebular 
hypothesis  explains  the  peculiarities  of  the  solar  system, 
we  must  inquire  what  are  the  most  important  of  these 
peculiarities.  We  will  take  these  from  Young's  general 
book  on  Astronomy,  from  which  most  of  the  facts  in  this 
chapter  have  been  condensed.  They  are  as  follows: 

The  orbits  of  nearly  all  the  planets  and  their  satellites 
are  nearly  circular;  they  are  all  in  the  same  plane;  and  all 


LAPLACE'S  NEBULAR  HYPOTHESIS        163 

revolve  in  the  same  direction.  They  are,  moreover,  with 
the  single  exception  of  Neptune,  arranged  at  distances 
from  the  sun  in  accordance  with  Bode's  Law. 

All  the  planets  increase  in  both  directions,  towards  and 
from  the  sun,  in  density  from  Saturn,  the  least  dense. 

All  the  planets,  with  the  exception  probably  of  Uranus, 
rotate  in  a  plane  that  is  nearly  the  same  as  the  plane  of 
the  orbit  in  which  they  revolve.  Moreover,  with  the 
exception  of  probably  both  Uranus  and  Neptune,  all  the 
planets  rotate  in  the  same  direction  as  that  in  which  they 
revolve. 

The  satellites  revolve  in  orbits  whose  planes  nearly 
coincide  with  the  plane  of  the  planets'  rotation,  while  the 
direction  of  the  revolution  of  the  satellites  is  the  same  as 
that  in  which  their  planets  revolve. 

Finally,  the  largest  planets  rotate  most  swiftly. 

Now,  LaPlace's  nebular  hypothesis  explains  nearly  all 
of  the  above  facts.  The  following  modifications  of  the 
hypothesis,  however,  are  necessary.  Let  us  briefly  ex- 
amine some  of  these  modifications. 

In  the  first  place  it  can  be  shown  that  the  original 
nebulous  mass  instead  of  being  at  a  higher  temperature 
than  that  of  the  sun  was  probably  at  a  much  lower  tem- 
perature, since  the  condensation  of  the  gaseous  matter 
must  have  increased  the  temperature.  Instead,  therefore, 
of  the  original  nebulous  mass  being  purely  gaseous  it  was, 
as  Young  expressed  it:  "Rather  a  cloud  of  ice  cold 
meteoric  dust  than  an  incandescent  gas  or  a  fire  mist." 
Or  in  other  words,  the  original  nebulous  mass  from  which 
the  solar  system  was  evolved,  consisted  of  finely  divided 
particles  of  solid  or  liquid  matter  surrounded  by  an  en- 
velope of  permanent  gaseous  matter. 

A  doubt,  too,  has  been  raised  as  regards  the  manner  in 
which  the  planets  were  liberated  from  the  central  sun. 


164         VOLCANOES  AND  EARTHQUAKES 

Instead  of  separating  in  the  form  of  a  regular  ring,  it  has 
been  thought  that  probably  in  most  cases  this  separation 
assumed  the  shape  of  a  lump.  It  might,  however,  have 
occurred  at  times  in  the  ring-like  form  as  may  be  seen  in 
the  case  of  the  planet  Saturn. 

Again,  instead  of  the  outer  rings  being  separated  first, 
and  the  others  in  regular  order,  so  that  the  outer  planets 
are  much  the  older,  it  would  seem  possible,  or,  as  Young 
states,  even  probable,  that  several  of  the  planets  may  be 
of  the  same  or  nearly  the  same  age,  as  they  would  be  if 
more  than  one  ring  had  been  separated  at  one  time,  or, 
indeed,  several  planets  may  have  been  formed  from 
different  zones  of  a  single  ring. 

As  you  will  see,  LaPlace's  nebular  hypothesis  assumes 
that  both  sun  and  moon  were  in  a  highly  heated  condition 
when  they  were  separated  from  the  nebulous  sun,  so  that 
we  can  understand  that  the  former  molten  condition  of 
their  interiors  was  due  to  the  heat  they  originally  possessed. 


CHAPTER  XIX 

THE  EARTH'S  HEATED  INTERIOR,  THE  CAUSE  OF  VOLCANOES 

As  we  have  already  seen,  the  nebular  hypothesis  of 
LaPlace  would  seem  to  make  it  more  than  probable 
that  the  earth  was  originally  in  a  highly  heated  condition, 
and  only  reached  its  present  state  after  long  cooling. 
While  this  cooling  has  gone  on  for  probably  millions  upon 
millions  of  years  both  before  and  during  the  geological 
past,  yet  in  the  opinion  of  perhaps  the  best  geologists 
the  interior  of  the  earth  is  still  very  hot,  only  the  outer 
portions  or  crust  having  hardened  by  loss  of  heat. 

That  there  is  a  very  hot  region  somewhere  inside  the 
earth  is  evident,  since  from  some  place  or  places  below 
the  surface  there  come  out  the  immense  streams  of  lava 
that,  continuing  to  flow  at  irregular  intervals,  have  at 
last  built  up  such  great  masses  of  land  as  the  island  of 
Hawaii,  the  still  greater  island  of  Iceland,  the  even 
greater  lava  fields  of  the  western  United  States,  and  the 
great  plateau  of  the  Deccan  in  southern  Hindustan. 

It  certainly  must  have  required  a  great  quantity  of  lava 
to  build  up  an  island  like  Hawaii  with  its  area  of  fully 
40,000  square  miles,  for  the  highest  point  on  the  summit 
of  Mt.  Kea  reaches  13,805  feet  above  the  level  of  the  sea, 
and,  moreover,  stands  on  the  bed  of  the  Pacific  Ocean 
in  water  fully  12,000  feet  deep. 

But  Iceland  is  only  one  of  many  similar  cases.  Vol- 
canoes are  to  be  found  in  practically  all  parts  of  the  earth, 
not  only  in  the  equatorial  regions,  where  they  are  es- 
[165] 


166          VOLCANOES  AND  EARTHQUAKES 

pecially  numerous,  but  also  in  the  frigid  and  temperate 
zones.  We  must  also  remember  the  immense  lava  streams 
that  are  known  to  have  come  from  the  interior  during 
the  great  fissure  eruptions  of  the  geological  past.  When 
all  these  facts  are  taken  into  consideration,  it  would  cer- 
tainly seem  that  there  is  only  one  source  sufficiently  great 
to  supply  this  wonderful  demand,  and  that  is  the  entire 
inside  of  the  earth. 

But  entirely  apart  from  volcanic  phenomena  there  are 
other  proofs  that  the  entire  interior  of  the  earth  is  in  a 
highly  heated  condition.  The  differences  of  temperature 
caused  by  the  sun  during  day  and  night  do  not  affect  the 
earth  much  below  a  depth  of  three  feet,  while  the  differ- 
ences of  temperature  between  summer  and  winter  do  not 
extend  much  further  below  the  surface  than  forty  feet. 
Below  these  depths,  in  all  parts  of  the  earth,  the  tempera- 
ture of  the  crust  rises  at  a  rate,  which,  although  not  uni- 
form, yet  is  not  far  from  an  increase  of  one  degree  of  the 
Fahrenheit  thermometer  scale  for  every  fifty  or  sixty  feet 
of  descent. 

If  the  above  rate  of  increase  continues  uniform  the  tem- 
perature of  the  crust  would  be  sufficiently  hot  to  boil 
water  at  a  distance  of  about  8,000  feet  below  the  surface, 
while  at  a  depth  of  about  thirty  miles  the  temperature 
would  be  sufficiently  high  to  melt  all  known  substances 
at  ordinary  conditions  of  atmospheric  pressure;  that  is, 
to  melt  all  known  substances  if  they  were  subjected  to 
such  a  temperature  at  the  level  of  the  sea. 

In  considering  the  above  we  must  not  lose  sight  of  the 
fact  that  this  increase  in  temperature  with  descent  below 
the  surface  of  the  earth's  crust  occurs,  not  only  in  places 
where  there  are  volcanoes,  but  over  all  parts  of  the  earth, 
thus  seeming  to  point  out  that  there  is  something  hot  be- 
low the  surface  which  fills  the  entire  inside  of  the  earth. 


THE  CAUSE  OF  VOLCANOES  167 

It  is  true  the  greatest  distance  to  which  man  has  actually 
gone  down  through  the  earth's  crust  is  but  a  few  miles. 
We  do  not,  therefore,  know  by  actual  experience  that  the 
interior  is  anywhere  in  a  fused  condition,  yet  the  escape 
of  lava  or  molten  rocks  in  all  latitudes,  and  in  the  enor- 
mous quantities  referred  to  above,  seems  to  show  that 
the  entire  inside  of  the  earth  is  at  a  temperature  suffi- 
ciently high  to  melt  all  known  substances  under  ordinary 
conditions. 

It  may  be  interesting  in  this  connection  to  examine 
some  of  the  proofs  of  this  increase  in  temperature  with 
descent  below  the  surface.  The  following  figures  are 
given  by  Dana: 

Borings  to  great  depths  have  been  made  in  various  parts 
of  the  earth,  both  for  artesian  wells  as  well  as  for  the 
shafts  of  mines.  After  passing  the  line  of  invariable 
temperature,  the  rate  of  increase  for  a  total  distance  of 
4,000  feet  below  the  surface  is  in  the  neighborhood  of 
from  one  degree  for  fifty-five  to  sixty  feet,  or  an  average 
of  fifty-seven  and  a  half  feet  for  each  degree  of  heat.  In 
the  case  of  the  deep  artesian  well  bored  at  Grenelle,  Paris, 
where  a  temperature  of  eighty-five  degrees  Fahrenheit 
was  reached  at  a  distance  of  2,000  feet,  the  rate  of  in- 
crease was  somewhat  more  rapid,  being  one  degree  Fahren- 
heit for  every  sixty  feet. 

In  a  deep  well  bored  in  a  salt  mine  at  Neusalzwerk, 
Prussia,  a  depth  of  2,200  feet  showed  a  temperature  of 
ninety-one  degrees  Fahrenheit  at  the  bottom.  This  was 
at  the  rate  of  one  degree  for  every  fifty  feet  of  descent. 
At  Schladenbach,  in  Prussia,  a  well  has  been  dug  to  the 
depth  of  5,735  feet  with  a  temperature  of  134°  F.  A 
boring  at  Wheeling,  in  West  Virginia,  reached  a  depth  of 
4,500  feet,  3,700  feet  below  the  level  of  the  sea.  Here 
the  rate  of  increase  of  temperature  in  the  upper  half  was 


168         VOLCANOES  AND  EARTHQUAKES 

one  degree  Fahrenheit  for  every  eighty  feet,  and  in  the 
lower  half  of  one  degree  for  every  sixty  feet. 

It  must  not  be  supposed  because  the  rate  of  increase 
of  temperature  is  not  uniform  that  the  argument  of  a 
highly  heated  interior  is  weakened.  On  the  contrary,  it 
would  be  very  surprising  if  the  rate  continued  uniform; 
for  it  is  evident  that  the  conducting  power  of  different 
materials  in  the  earth's  crust  for  heat  must  necessarily 
make  a  great  difference  in  the  rate  at  which  heat  should 
increase,  as  we  go  farther  down  into  the  earth.  This  is 
so  important  a  matter  that  I  will  explain  it  at  somewhat 
greater  length. 

Let  us  suppose  that  instead  of  the  highly  heated  interior 
of  the  earth,  we  consider  the  simple  case  of  a  hot  stove, 
the  doors  or  other  openings  into  which  are  closed  so  that 
it  is  impossible  to  see  the  red  hot  coals  inside.  Now, 
suppose  holes  were  bored  in  the  sides  of  this  stove  not 
deep  enough  to  reach  the  red  hot  mass  within,  and  that 
tightly  fitting  rods  or  plugs  all  of  the  same  length  and 
thickness,  but  of  different  kinds  of  materials  such  as  wood, 
earthenware,  glass,  iron,  copper,  silver,  and  gold,  etc.,  were 
so  placed  in  the  holes  as  to  tightly  fit  them.  Now,  under 
these  circumstances  the  end  of  all  the  plugs  would  be  at 
the  same  distance  from  the  heated  inside.  They  would 
not,  however,  by  any  means  show  the  same  temperatures, 
the  metallic  rods  would  be  too  hot  to  touch,  while  the 
end  of  the  piece  of  wood  would  hardly  be  hot  enough  to 
burn  the  hand  when  held  against  it.  The  piece  of  glass 
and  earthenware  though  less  cool  would  be  much  less  hot 
than  the  different  rods  of  metals.  Their  temperatures 
would  be  necessarily  affected  by  their  conducting  power 
for  heat.  The  wood,  the  glass,  and  the  earthenware 
being  poorer  conductors  than  the  metals  would  show 
much  lower  temperatures. 


THE  CAUSE  OF  VOLCANOES  169 

Now,  the  same  thing  is  true  with  the  different  materials 
that  constitute  the  rocks  of  the  earth's  crust.  Some  of 
these  are  much  better  conductors  of  heat  than  others,  so 
that  the  rate  of  increase  of  temperature  with  descent 
below  the  surface  must  necessarily  vary  with  the  kind  of 
materials  that  form  the  crust  of  different  parts  of  the 
earth. 

You  may,  therefore,  safely  conclude  that  the  entire 
interior  of  the  earth  is  in  a  highly  heated  condition,  and 
that  the  source  of  this  heat  is  to  be  traced  to  the  heat  the 
earth  originally  possessed  when,  in  accordance  to  the  nebu- 
lar hypothesis  of  LaPlace,  it  was  separated  from  the  sun 
which  gave  birth  to  it,  that  the  present  crust  of  the  earth 
has  been  formed  on  the  outside  by  the  loss  of  a  portion 
of  this  heat. 

The  rapidity  with  which  a  body  cools,  depends,  among 
other  things,  on  the  difference  between  its  temperature 
and  that  of  the  medium  in  which  it  is  placed.  The  greater 
this  difference  of  temperature  the  greater  the  rapidity  of 
cooling.  Careful  measurements  made  by  Tait,  the  Eng- 
lish physicist,  show  that  our  earth  loses  every  year  from 
each  square  foot  of  surface,  an  amount  of  heat  that  would 
be  able  to  raise  the  temperature  of  one  pound  of  water 
from  the  melting  point  of  ice  to  the  boiling  point  of  water, 
or  from  32°  F.  to  212°  F.  The  rate  of  loss  of  heat,  must, 
therefore,  have  been  much  greater  when  the  earth  was 
more  highly  heated  than  it  is  now,  and  will  be  much 
smaller  than  now  many  years  from  the  present. 

Now,  let  us  suppose,  what  nearly  everyone  acknowl- 
edges to  be  true,  that  the  earth  was  originally  so  hot  as 
to  be  a  molten  globe,  and  that  while  in  this  molten  con- 
dition, it  began  to  revolve  or  move  around  the  sun.  Since 
the  empty  space  through  which  the  earth  moves  is  very 
cold,  something  in  the  neighborhood  of  45°  below  the 


170          VOLCANOES  AND  EARTHQUAKES 

zero  of  the  Fahrenheit  thermometer  scale,  the  loss  of 
heat  would  take  place  very  rapidly  and  a  thin  crust  of 
hardened  materials  would  be  formed  on  the  outside. 
Now  all  the  time  the  earth  is  cooling,  it  is  shrinking  or 
growing  smaller. 

A  very  little  thought  will  convince  you  that  this  cool- 
ing or  shrinkage  could  not  go  on  uninterruptedly;  for, 
while  the  earth  was  cooling  it  was  contracting,  or  growing 
smaller,  and  in  this  way  a  great  pressure,  or  as  it  is  generally 
called  in  science,  a  great  stress  was  being  produced.  Every 
now  and  then  this  stress  became  so  great  that  the  crust 
of  the  earth  was  fractured  or  broken. 

At  first  these  fractures  would  not  require  a  very  great 
amount  of  stress  or  force,  since  the  crust  of  lava  was  then 
very  thin.  After  great  periods  of  time,  however,  the 
crust  grew  thicker  and  thicker,  and  the  amount  of  force 
required  to  break  it  continually  increased,  so  that  the 
fractures  of  the  crust  produced  a  greater  disturbance. 

Whenever  the  earth's  crust  was  fractured  in  this  way 
the  earth  was  shaken  by  what  are  called  earthquakes, 
while  a  part  of  the  molten  interior  would  run  out  or 
escape,  making  volcanoes.  In  the  very  early  times 
neither  the  earthquakes  or  the  volcanoes  were  as  ener- 
getic as  they  were  at  later  periods  when  the  thickness 
of  the  earth's  crust  increased. 

Now,  having  as  we  believe  correctly  come  to  the  con- 
clusion that  the  entire  interior  of  the  earth  is  in  a  highly 
heated  condition,  the  next  question  that  arises  is  as  to 
the  present  condition  of  this  interior.  A  long  time  ago 
it  was  believed  that  the  interior  of  the  earth  is  still 
melted,  and  that  a  cooled  portion  or  crust  surrounds 
a  great  molten  mass  that  fills  all  the  inside;  that  it 
is  this  mass  which  supplies  the  immense  quantities  of 
molten  rock  or  lava  that  escape  through  the  craters  of 


THE  CAUSE  OF  VOLCANOES  171 

volcanoes  or  through  the  fissures  in  the  crust.  Without 
going  into  this  question  thoroughly,  since  it  is  a  very 
difficult  question  to  understand,  it  will  be  sufficient  to 
say  that  there  are  many  reasons  why  it  is  impossible 
to  believe  that  the  interior  is  still  melted. 

You  will  understand  that  if  the  interior  of  the  earth 
were  melted  like  a  huge  central  sea  of  fire  that  each 
volcano  would  necessarily  affect  all  the  others.  Now, 
as  we  have  seen,  this  is  never  the  case,  so  that  this  is  one 
reason  we  cannot  believe  in  the  existence  of  a  melted 
interior. 

Another  reason  we  cannot  believe  in  a  molten  interior  is 
an  astronomical  consideration.  It  can  be  shown  that  un- 
der the  attraction  of  the  sun  and  moon  the  earth  could  not 
possibly  behave  as  it  does  if  it  were  still  liquid  in  the 
interior.  That,  on  the  contrary,  the  behavior  of  the 
earth  to  the  attraction  of  the  sun  and  moon  is  such  as 
to  make  it  necessary  for  us  to  believe  that  it  is  as  rigid 
throughout  as  would  be  a  globe  of  steel  of  the  same  size. 

I  can  easily  understand  that  you  find  it  very  difficult 
to  see  how  it  can  be  believed  that  the  interior  of  the 
earth  is  solid  and  yet  at  the  same  time  be  sufficiently 
hot  to  melt.  I  can  imagine  hearing  you  ask  if  it  is  hot 
enough  in  the  inside  to  melt  any  known  materials,  why 
it  is  not  melted.  The  reason,  however,  is  very  simple 
when  you  come  to  think  it  over.  For  a  solid  to  fuse  or 
become  melted,  it  is  not  only  necessary  for  it  to  be  heated 
to  a  temperature  which  is  different  for  different  sub- 
stances, but  that  at  the  same  time  it  is  heated  it  shall 
have  plenty  of  room  in  which  to  expand  or  grow  bigger. 
In  other  words,  the  temperature  required  to  fuse  any 
substance  increases  very  rapidly  with  the  pressure  to 
which  that  substance  is  exposed. 

Now,  try  to  think  of  the  pressure  to  which  the  ma- 


172         VOLCANOES  AND  EARTHQUAKES 

terials  that  fill  the  inside  of  the  earth  are  subjected 
at  great  distances  below  the  surface.  This  pressure  is 
enormous,  not  only  by  reason  of  the  weight  of  the 
many  miles  of  rocks  that  are  pressing  down,  but  also 
by  reason  of  the  enormous  stress  or  pressure  caused  by 
contraction  or  shrinkage.  When  we  say  that  the  interior 
of  the  earth  is  hot  enough  to  melt  all  known  substances 
we  mean  hot  enough  to  melt  them  if  they  could  be  brought 
from  great  depths  to  the  level  of  the  sea,  but  not  hot 
enough  to  melt  them  when  subjected  to  the  great  pres- 
sure that  exists  in  regions  far  below  the  surface  of  the 
earth. 

Briefly,  the  condition  of  things  is  believed  to  be  as 
follows:  The  entire  interior  is  filled  with  rock  hot  enough 
to  melt  at  the  level  of  the  sea,  but  under  too  great  pressure 
to  melt.  If  this  be  granted,  as  it  is  by  perhaps  the 
greatest  number  of  men  who  are  competent  to  judge, 
the  phenomena  of  earthquakes  can  be  readily  explained, 
as  can,  indeed,  the  phenomena  of  those  great  movements 
whereby  great  changes  of  level  take  place  in  different 
parts  of  the  earth. 

Now  let  us  see  how  volcanoes  can  be  explained  on  the 
assumption  that  the  interior  of  the  earth  is  hot  enough 
to  melt,  but  remains  solid  only  because  there  is  no  room 
for  the  heated  mass  to  expand  in.  Such  a  heated  interior 
as  we  have  imagined,  must  be  constantly  losing  its  heat 
and,  therefore,  shrinking.  Every  now  and  then  this 
shrinkage  must  produce  great  fissures  or  cracks  in  the 
solid  crust  of  the  earth.  Now  should  such  cracks  or 
fissures  extend  downwards  to  the  heated  interior,  there 
must  result  a  decrease  in  the  pressure.  The  rocks  would, 
therefore,  begin  to  expand  and  would  be  forced  by  the 
great  pressure  to  rise  slowly  in  such  cracks  or  fissures. 
The  further  they  rise  the  greater  the  relief  of  pressure, 


THE  CAUSE  OF  VOLCANOES  173 

until  they  at  last  assume  a  molten  condition  in  which 
they  are  forced  out  through  the  craters  of  volcanoes 
as  molten  rocks  or  lava. 

But  it  is  not  only  volcanoes  that  seem  to  indicate  a 
highly  heated  plastic  condition  as  existing  in  the  earth's 
interior.  As  geologists  well  know,  there  are  to  be  found 
in  the  various  strata  of  the  earth  places  where  great 
fissures  have  been  made  at  various  times  during  the 
geological  past.  These  fissures  vary  in  width  from  a 
few  inches  to  many  hundreds  of  feet,  and  are  frequently 
scores  of  miles  in  length.  Lava  either  flows  out  of  them, 
and  covers  adjoining  sections  of  the  country,  or  simply 
rises  in  them  and,  afterwards  cooling,  forms  dikes.  In 
many  instances,  however,  the  lava  is  forced  in  between 
more  or  less  horizontal  layers  and  in  some  cases  has 
caused  these  layers  to  assume  the  shape  of  what  geol- 
ogists know  as  subtruderant  mountains.  Some  of  the 
eastern  ranges  of  the  Rocky  Mountains  have  been  formed 
in  this  manner. 

We  can,  therefore,  picture  to  ourselves  the  following 
as  the  manner  of  formation  of  an  ordinary  volcano. 
A  fissure  is  first  formed  in  the  solid  crust  of  the  earth, 
extending  downwards  to  the  regions  of  great  heat.  There 
is  thus  produced  a  relief  of  pressure,  so  that  at  this  point 
the  highly  heated  rocks  begin  to  be  slowly  forced  up 
through  the  fissure.  As  they  rise  higher  and  higher 
they  become  less  solid  and  finally  expand  into  fused 
masses  that  can  flow  out  of  the  crater  or  opening  in  the 
earth's  surface.  In  this  way  a  volcano  is  started. 

But  for  this  volcano  to  continue  in  eruption,  it  is 
necessary  that  the  conditions  shall  continue  that  force 
the  molten  rock  upwards  from  great  depths.  It  is  not 
enough  for  the  lava  to  fill  the  crevice  that  exists  upwards 
to  the  surface,  it  must  continue  to  be  forced  upwards 


174          VOLCANOES  AND  EARTHQUAKES 

until  it  escapes.  If  it  is  permitted  to  remain  in  the 
fissure  for  any  time,  it  hardens,  and  only  great  dikes 
are  formed.  It  would  seem,  therefore,  that  some  other 
force  must  be  called  into  action  to  keep  the  fissure  open 
or,  in  other  words,  to  prevent  the  chilling  of  the  lava. 
Now,  this  force  is  generally  believed  to  be  the  expansive 
force  of  steam  or  the  vapor  of  water. 

As  Dana  points  out,  by  far  the  greater  part  of  the 
vapor  which  escapes  from  the  craters  of  volcanoes  con- 
sists of  steam  or  the  vapor  of  water.  Indeed,  it  can 
be  shown  that  for  every  hundred  parts  of  different 
vapors,  at  least  ninety-nine  of  such  parts  consist  of 
water  vapor.  It  is  for  the  greater  part,  to  the  pressure 
of  steam  or  water  vapor  that  the  escape  of  lava  from 
the  tube  near  the  top  of  the  crater  is  due. 

Of  course,  the  question  arises  as  to  where  the  water 
comes  from  that  produces  this  steam.  There  are  three 
possible  sources.  From  the  rains;  from  leakage  at  the 
bed  of  the  ocean;  and  from  vapors  existing  at  great  depths 
below  the  surface. 

It  is  not  probable  that  either  rain  water,  or  water 
from  the  ocean,  penetrates  through  the  earth's  crust 
for  distances  much  greater  than  a  few  thousand  feet. 
It  is,  however,  very  well  known  that  in  all  parts  of  the 
earth,  except  in  desert  regions,  whether  they  are  near  or 
far  from  the  ocean,  the  rocks  are  always  found  fully 
charged  with  water.  When,  therefore,  the  slowly  rising 
lava  passes  through  the  moist  rocks  that  everywhere 
form  the  crust  of  the  earth,  there  must  be  formed  in  them 
great  quantities  of  steam  under  very  high  pressure. 
Moreover,  many  substances,  especially  those  forming 
lava,  possess  the  power  of  absorbing  large  quantities 
of  steam  and  other  gases.  Therefore,  as  the  molten 
material  reaches,  the  moist  rocks  in  the  earth's  crust, 


THE  CAUSE  OF  VOLCANOES  175 

it  becomes  highly  charged  with  steam,  and  as  the  lava 
rises  towards  the  surface  this  steam  expands. 

Where  the  lava  is  in  a  very  fluid  condition  the  steam 
quietly  escapes,  as  does  the  steam  from  the  surface  of 
boiling  water.  But  where  the  lava  is  viscous,  like  tar 
or  pitch,  great  bubbles  are  formed,  which,  on  their  ex- 
plosion, throw  the  lava  upwards  for  great  distances 
into  the  air. 

We  can,  therefore,  account  in  this  manner  for  both 
the  non-explosive  as  well  as  the  explosive  type  of  vol- 
canoes. 

It  must  not  be  supposed,  however,  that  it  is  the  ex- 
plosive power  of  steam  which  is  the  principal  cause  of 
the  lava  rising  upwards  from  great  depths.  This  is 
caused  by  the  great  pressure  or  stress  set  up  by  the  con- 
traction of  a  cooling  crust.  The  pressure  of  this  steam 
is  added  to  this  pressure  which  keeps  the  lava  flowing 
upwards  from  great  depths  below. 

The  objection  has  sometimes  been  urged  that  it  is 
impossible  to  believe  the  lava  comes  from  a  highly 
heated  interior,  because,  as  is  well  known,  lavas  are  of 
different  types  even  when  coming  from  the  same  volcano 
at  different  times  of  eruption.  While  such  an  objection 
would  have  weight  were  it  believed  that  the  interior 
of  the  earth  is  still  in  a  molten  condition,  it  loses  its 
weight  when  one  believes  that  the  interior  is  solid.  It 
must,  however,  be  acknowledged  that  the  largest  part 
of  the  interior  of  the  earth  would  probably  have  the 
same  chemical  composition  if  it  had  ever  been  in  a  com- 
pletely melted  condition  throughout. 

I  do  not  doubt  you  have  already  concluded  that  the 
reason  the  earth's  volcanoes  are  practically  limited  to  the 
borders  of  continents,  or  to  the  shores  of  islands,  is  the 
leakage  of  the  ocean  waters  into  the  crust  at  these  parts. 


176          VOLCANOES  AND  EARTHQUAKES 

This  was  at  one  time  believed  by  most  geologists.  That 
sea  water  has  much  to  do  with  such  volcanoes  as  Vesuvius 
there  is  no  doubt,  but  it  is  now  generally  recognized  that 
it  is  not  so  much  the  present  outlines  of  the  earth,  or  the 
present  arrangement  of  its  land  and  water  areas,  that  de- 
termines the  distribution  of  the  world's  volcanoes.  It  is 
rather  believed  that  the  location  of  the  lines  of  fractures 
along  which  the  earth's  volcanoes  are  found  were  deter- 
mined by  conditions  that  occurred  long  before  the  earth 
assumed  its  present  outlines. 

But  there  is  another  explanation  that  has  been  sug- 
gested as  regards  the  condition  of  the  interior  of  the  earth. 
Judd  refers  to  this  explanation  as  follows: 

"Some  physicists  have  asserted  that  a  globe  of  liquid 
matter  radiating  its  heat  into  space,  would  tend  to 
solidify  both  at  the  surface  and  the  centre  at  the  same 
time.  The  consequence  of  this  action  would  be  the  pro- 
duction of  a  sphere  with  a  solid  external  shell  and  a  solid 
central  nucleus,  but  with  an  interposed  layer  in  a  fluid 
or  semi-fluid  condition.  It  has  been  pointed  out  that 
if  we  suppose  the  solidification  to  have  gone  so  far  as 
to  have  caused  the  partial  union  of  the  interior  nucleus 
and  the  external  shell,  we  may  conceive  a  condition  of 
things  in  which  the  stability  and  rigidity  is  sufficient 
to  satisfy  both  geologists  and  astronomers,  but  that  in 
still  unsolidified  pockets  or  reservoirs,  filled  with  liquefied 
rock,  between  the  nucleus  and  the  shell,  we  should  have  a 
competent  cause  for  the  production  of  the  volcanic 
phenomena  of  the  globe.  In  this  hypothesis,  however, 
it  is  assumed  that  the  cooling  at  the  centre  and  the  sur- 
face of  the  globe  would  go  on  at  such  rate  that  the  res- 
ervoirs of  liquid  material  would  be  left  at  a  moderate 
depth  from  the  surface,  so  that  easy  communication 
could  be  opened  between  them  and  volcanic  vents." 


THE  CAUSE  OF  VOLCANOES  177 

I  must  caution  you,  however,  not  to  think  that  the 
above  theory  of  volcanoes  is  accepted  by  all  scientific  men. 
On  the  contrary,  there  are  many  who  believe  that  the 
earth  is  solid  throughout  because  it  has  completely  lost 
its  original  heat;  that  it  is  only  comparatively  small 
areas  that  are  to  be  found  filled  with  molten  or  at  least 
highly  heated  material.  But  these  opinions  are  held 
largely  by  those  who  have  given  their  attention  almost 
entirely  to  the  phenomena  of  earthquakes,  or  who  base 
their  reasonings  on  mathematical  grounds  only  and  have 
not  sufficiently  considered  the  phenomena  of  volcanoes. 
Since,  however,  they  can  be  better  understood  after  we 
have  explained  the  phenomena  of  earthquakes,  we  will 
defer  their  discussion  to  the  last  chapters  of  this  book. 


CHAPTER  XX 

SOME  FORMS  OF  LAVA 

In  describing  the  wonders  of  volcanoes,  we  must  not 
fail  to  say  something  of  the  many  remarkable  forms  that 
lava  is  capable  of  assuming. 

All  volcanic  lavas  contain  large  quantities  of  an  acid 
substance  known  as  silica,  or  what  is  known  better  as 
quartz  sand.  This  material  exists  in  lava  combined 
chemically  with  various  substances  called  bases,  the 
principal  of  which  are  alumina,  magnesia,  lime,  iron, 
potash,  and  soda. 

Although  there  are  many  kinds  of  lava,  yet  all  lavas 
can  be  arranged  under  three  great  classes  according  to 
the  quantity  of  silica  they  contain. 

Add  lavas  are  those  in  which  the  quantity  of  silica 
is  greatest.  In  these  lavas  the  silica,  which  varies  from 
66  to  80%,  is  combined  with  small  quantities  of  lime  or 
magnesia,  and  comparatively  large  quantities  of  potash 
or  soda.  Some  of  the  most  important  varieties  of  acid 
lavas  are  known  as  trachytes,  andesites,  rhyolites,  and 
obsidians. 

Basic  lavas  are  those  containing  from  45  to  55%  of 
silica.  They  are  rich  in  lime  and  magnesia,  but  poor 
in  soda  or  potash.  Some  of  the  most  important  of  basic 
lavas  are  the  dolerites  and  basalts.  Generally  speaking, 
basic  lavas  are  of  a  darker  color  than  acid  lavas,  and  fuse 
at  much  lower  temperatures. 

Intermediate  lavas  are  those  containing  silica  in  the 
proportion  of  from  55  to  66%. 
[178] 


SOME  FORMS  OF  LAVA  179 

While  the  temperature  of  liquid  lava  has  not  been  very 
accurately  determined,  yet,  since  we  know  that  molten 
lava  is  able  to  melt  silver  or  copper,  its  temperature 
must  be  somewhere  between  2,500°  F.  and  3,000°  F., 
the  melting  point  varying  with  the  chemical  composition. 

According  to  Dana  lavas  can  be  divided  into  the  fol- 
lowing classes  according  to  their  fusibility;  i.  e.,  lavas 
of  easy  fusibility,  such  as  basalts;  these  lavas  fuse  at  about 
2,250°  F.;  lavas  of  medium  fusibility,  including  andesites; 
these  lavas  fuse  at  about  2,520°  F.;  lavas  of  difficult 
fusibility,  such  as  trachytes;  these  lavas  fuse  at  about 
2,700°  F. 

But  what  is,  perhaps,  most  curious  about  lavas  is  that 
when  the  surface  of  a  freshly  broken  piece  of  cold  lava 
is  carefully  examined,  it  is  found  to  contain  a  number 
of  small  crystals  of  such  mineral  substances  as  quartz, 
feldspar,  hornblende,  mica,  magnetite,  etc. 

The  best  way  to  study  the  different  forms  of  lava 
crystals  is  to  prepare  a  thin  transparent  slice  of  hardened 
lava  and  then  examine  it  with  a  good  magnifying  glass. 
It  will  be  found  that  the  slice  consists  of  a  mass  of  a 
glass-like  material  through  which  the  crystals  are  ir- 
regularly distributed,  not  unlike  the  raisins  and  currants 
in  a  slice  of  not  over  rich  plumcake. 

When  examined  by  a  more  powerful  glass,  such  as  a 
microscope,  cloudy  patches  can  be  seen  distributed 
irregularly  through  the  glass-like  mass.  When  these 
patches  are  examined  by  a  higher  power  of  the  microscope 
they  are  seen  to  consist  of  small  solid  particles  of  definite 
forms  known  as  microliths  and  crystallites.  It  has  been 
shown  by  a  careful  study  of  these  minute  objects  that 
they  form  the  exceedingly  small  particles  of  which 
crystals  are  built  up. 

If  we  fuse  a  small  quantity  of  lava  and  then  let  it 


180         VOLCANOES  AND  EARTHQUAKES 

slowly  cool,  the  glassy  mass  will  be  found  to  contain 
numerous  crystallites.  On  the  other  hand,  when  fused 
lava  is  permitted  to  cool  quickly,  it  takes  on  the  form 
of  a  black,  glass-like  mass  known  as  obsidian  or  volcanic 
glass,  a  very  common  form  of  lava  in  some  parts  of  the 
world. 

In  some  lavas  there  are  found  larger  crystals  that 
appear  to  have  been  separated  from  the  glassy  mass, 
under  the  great  pressure  that  exists  in  the  subterranean 
reservoirs  at  great,,  depths  below  the  volcanic  crater, 
and  then  floated  to  the  surface  surrounded  by  the  glass- 
like  material.  Now  when  we  examine  these  crystals 
with  -a  higher  power  of  the  microscope,  we  frequently 
find  in  them  minute  cavities  containing  a  small  quantity 
of  liquid  and  a  bubble  of  gas,  thus  causing  them  to  re- 
semble small  spirit  levels.  The  liquid  in  such  cavities 
has  been  examined  chemically  and  in  most  cases  has  been 
found  to  consist  of  water  containing  several  salts  in  solu- 
tion. Sometimes,  however,  the  liquid  consists  of  liquefied 
carbonic  acid  gas.  These  wonderful  things  will  be  dis- 
cussed at  greater  length  in  the  Wonder  Book  of  Light. 

When  the  mass  of  molten  rock  or  lava  that  comes 
out  of  the  crater  of  a  volcano  is  thrown  upwards  in  the 
air  the  condition  it  assumes  by  the  time  it  falls  back 
again  to  the  earth  depends  on  the  height  it  reaches. 
If  this  height  is  great  the  lava  chills  or  hardens  before 
reaching  the  earth,  and  assumes  various  forms  according 
to  the  size  of  the  fragments.  The  largest  of  these  frag- 
ments are  called  cinders;  the  finer  particles  volcanic  dust; 
while  most  of  those  of  intermediate  particles  are  known 
among  other  things  as  volcanic  ashes. 

We  have  already  seen  that  when  an  explosive  volcanic 
eruption  occurs  there  is  suddenly  thrown  out  of  the 
crater  of  the  volcano  a  huge  column  of  various  sub- 


SOME  FORMS  OF  LAVA  181 

stances  that  rises  sometimes  as  high  as  30,000  feet  or 
even  more.  The  smaller  fragments  of  lava  are  quickly 
cooled  and  form  volcanic  ashes,  sand,  cinders,  or  dust. 
These  are  rapidly  spread  out  by  the  wind  in  the  form  of 
a  black  cloud,  that  not  only  covers  the  mountain  but 
reaches  out  over  the  surrounding  country,  completely 
shutting  off  the  light  of  the  sun.  From  this  cloud  par- 
ticles of  red  hot  ashes,  cinders,  sand,  etc.,  begin  to  fall, 
the  largest  particles  near  the  crater  of  the  volcano,  and 
the  smaller  particles  at  much  greater,  distances.  In  very 
powerful  explosive  volcanic  eruptions  such  as  Krakatoa, 
the  finer  dust  may  be  carried  to  practically  all  parts  of 
the  world. 

Volcanic  ashes  consist  of  a  fine,  light,  gray  powder. 
These  particles  take  the  name  ashes  from  their  resemblance 
to  the  ashes  left  after  the  burning  of  pieces  of  wood  or 
coal  in  an  open  fire.  The  name,  however,  as  Geicke 
points  out,  is  unfortunate,  since  it  is  apt  to  lead  one  to 
suppose  that  volcanic  ashes  consist  of  some  burned 
material.  Such  an  idea  is  erroneous,  however,  since 
ashes  do  not  consist  of  anything  that  is  left  after  burning, 
but  merely  of  fine  particles  of  molten  rock  that  have 
hardened  by  cooling.  When  in  the  shape  of  what  is 
known  as  volcanic  dust  these  particles  are  so  exceedingly 
small  that  they  can  readily  make  their  way  through  the 
smallest  openings  in  a  closed  room  just  as  does  the  finest 
dust  in  the  rooms  of  our  houses  when  they  are  shut  up. 
There  are  cases  on  record  where  people  have  been  suffo- 
cated by  the  entrance  of  volcanic  dust  in  closed  rooms  to 
which  they  have  fled  for  safety  during  volcanic  eruptions. 

Volcanic  sand  consists  of  the  coarser  particles  of 
chilled  lava  that  are  partly  round  and  partly  angular. 
They  are  of  various  sizes  up  to  that  of  an  ordinary  pea. 
Volcanic  sand  is  formed  by  the  breaking  up  of  the  lava 


182         VOLCANOES  AND  EARTHQUAKES 

by  the  explosion  of  the  vapors  as  they  escape  from 
the  lava  on  relief  from  pressure.  Volcanic  dust  when 
examined  by  the  microscope  is  found  to  consist  of  very 
small  particles  that  are  more  or  less  crystalline. 

But  besides  the  above  there  are  larger  fragments 
known  as  lapilli,  consisting  of  rounded  or  angular  bits 
of  lava  varying  in  size  from  that  of  a  pea  to  an  ordinary 
black  walnut.  These  sometimes  consist  of  solid  frag- 
ments, but  are  usually  porous,  sometimes  so  much  so 
that  they  readily  float  on  water. 

A  curious  form  sometimes  assumed  by  lava  consists 
of  what  are  called  volcanic  bombs.  These  are  formed 
during  explosive  eruptions,  when  masses  of  liquid  lava 
are  hurled  high  up  into  the  air.  During  their  flight  they 
take  on  a  rotary  motion,  which  tends  to  make  them 
globular,  so  that  cooling,  while  still  revolving,  they 
assume  the  form  of  a  more  or  less  spherical  mass.  At 
times,  however,  they  are  still  sufficiently  soft  when  they 
strike  the  earth  to  be  flattened  out  in  the  form  of  flat 
cakes.  When  of  a  spherical  form  these  are  very  properly 
called  volcanic  bombs. 

That  volcanic  bombs  have  actually  been  subjected 
to  a  spinning  motion  while  in  the  air  can  sometimes  be 
shown  by  the  fact  that  masses  of  scoriae  are  frequently 
found  in  the  interior  with  air  cells  largest  at  the  centre 
of  the  bomb. 

Volcanic  bombs  are  sometimes  thrown  from  the  crater 
to  great  distances.  During  one  of  its  recent  eruptions, 
Cotopaxi  threw  out  bombs  that  fell  at  a  distance  of  nine 
miles  from  the  crater. 

According  to  Dana  another  form  of  lava  bombs  is 
sometimes  found  on  the  slopes  of  the  active  volcanoes 
of  Hawaii,  where  masses  of  lava  acquire  a  ball-like  shape 
while  rolling  down  an  inclination. 


na8 


SOME  FORMS  OF  LAVA  183 

What  are  sometimes  called  volcanic  bombs,  but  which 
are  more  properly  volcanic  vesicles,  are  produced  by 
small  fragments  of  lava  which  are  thrown  up  in  the  air 
for  only  a  moderate  height  and,  on  cooling,  assume  pear- 
like  forms.  Fig.  25  represents  the  appearance  of  volcanic 
vesicles.  The  direction  in  which  these 
vesicles  moved  through  the  air  while  in 
a  molten  state  is  indicated  by  their  f 
shape,  the  blunt  end  being  the  end  to-  f 

wards  which  the  particles  were  projected. 

But  by  far  the  greater  portion  of  the 
hardened  lava;  i.  e.,  the  coarser,  heavier       f     j 
particles,  fall  back  on  the  mountain,  and    i        f 
collecting   around  the  crater  build   up  jrom  Dan 
volcanic   cones,  as  already  described  in  °f  Geology 

the  case  of  mountains  of  the  Vesuvian  FlG'  25>  VOLCANIC 

VESICLES 

type. 

There  are  two  different  ways  in  which  the  melted 
lava  is  broken  up  into  fine  particles  when  it  is  thrown 
upwards  from  the  crater  of  the  volcano.  Nearly  all 
lava  contains  large  quantities  of  steam  that  are  shut 
up,  or  occluded  in  the  mass,  being  prevented  from  es- 
caping by  reason  of  the  pressure  to  which  the  lava  is 
subjected.  The  lava  is  released  from  this  pressure  as 
it  is  thrown  out  of  the  crater.  The  steam  or  gases  escape 
explosively  and  thus  break  the  lava  into  fine  liquid  spray, 
which  rapidly  hardens. 

There  is  another  way  in  which  small  particles  of  lava 
are  formed.  Sometimes  large  pieces  of  hardened  lava 
are  shot  upwards  into  the  air  with  a  velocity  as  great 
as  that  with  which  a  heavy  projectile  leaves  the  muzzle 
of  a  large  gun.  These  heavy  particles  striking  against 
one  another,  either  while  rising  or  falling,  are  broken  into 
smaller  fragments.  Sometimes,  indeed,  these  fragments 


184         VOLCANOES  AND  EARTHQUAKES 

fall  back  again  into  the  crater  from  which  they  are  again 
violently  thrown  out,  and  are  again  broken  into  smaller 
fragments  either  while  rising  or  falling. 

You  will,  probably,  remember  several  instances  of 
volcanic  eruptions  where  masses  of  rock  were  thrown 
violently  up  into  the  air  out  of  the  crater.  These  larger 
masses  are  known  as  volcanic  blocks.  They  probably 
consist  of  masses  of  hardened  lava  that  have  collected 
in  the  tube  of  the  volcano  during  some  of  its  periods  of 
inactivity.  Sometimes,  however,  they  consist  of  frag- 
ments of  rocks  that  are  not  of  volcanic  origin.  Cases 
are  on  record  where  volcanic  blocks  have  been  thrown 
out  of  the  craters  in  so  great  quantities  as  to  cover 
the  surface  of  many  square  miles  of  land  with  fragments 
hundreds  of  feet  deep. 

There  is  sometimes  formed  on  the  surface  of  a  pool  of 
lava  as  it  collects  in  the  craters  of  such  volcanoes  as 
Mt.  Loa  or  Kilauea,  when  the  volcanoes  are  not  in  erup- 
tion, a  material  resembling  froth  or  scum.  The  same 
thing  sometimes  occurs  on  the  surface  of  some  kinds 
of  lava  as  it  runs  down  the  side  of  the  mountain.  In  this 
way  a  very  light  variety  of  highly  cellular  lava  known 
as  pumice  stone  is  produced.  The  action  which  thus 
takes  place  is  not  unlike  that  which  occurs  during  the 
raising  of  a  lot  of  the  dough  from  which  bread  is  made, 
where  the  carbonic  acid  gas  which  is  formed  during  the 
raising  of  the  dough  expands,  and  produces  the  well- 
known  open  cellular  structure  of  well-raised  bread.  In 
the  case  of  pumice  stone,  however,  this  raising  goes  on 
to  such  an  extent  that  the  mass  consists  often  of  less 
than  2%  of  solid  matter,  the  remainder  being  a  tangled 
mass  of  air. 

Fragments  of  lava  that  possess  a  cellular  structure 
form  what  are  known  as  sconce.  The  lightest  of  all  kinds 


From  a  Stereograph,  Copyright,  by  Underwood  &  Underwood 

THE  LAVA  FLOW  OF  THE  CRATER  OF  KILAUEA,  HAWAIIAN  ISLANDS 


SOME  FORMS  OF  LAVA  185 

of  scoriae  is  what  is  known  as  thread-lace  sconce.  Here 
the  thin  walls  consist  of  mere  threads.  Figs.  26  and  27 
represent  the  appearance  of  thread-lace  scoriae  from 
Kilauea.  The  separate  threads  are  very  fine,  being  only 

from  one-thirtieth  to  one- 
fortieth  of  an  inch  in 
thickness.  As  can  be 
seen,  this  form  of  scoriae 
have  six-sided  or  hexa- 
gonal shapes.  You  can 
form  some  idea  of  the 
great  lightness  of  such 
scoriae  when  you  learn 
that  they  contain  only 
1.7%  of  rocky  material. 
From  Dana's  Manual  of  Geology  "  Indeed,  they  contain  so 

FIG.  26.  THREAD-LACE  SCORIA  FROM   little  golid  material  that 

JllLAUEA  . 

a  layer  of  volcanic  glass 

only  one  inch  thick,  if  blown  out  into  scoriae,  would  be 
able  to  produce  a  layer  sixty  inches  thick. 

Another  curious  form  some- 
times assumed  by  lava,  especially 
in  the  case  of  Kilauea,  is  where 
the  lava  is  spun  out  in  the  form 
of  long  silk-like  hairs.  This  is 
called  by  the  natives  Pete's  hair, 
after  the  name  of  their  goddess. 
Inasmuch  as  the  origin  of  this 
form  of  lava  was  at  one  time 

generally    attributed    tO     the     aC-    From  Dana's  Manual  of  Geology 
f    .,          .     ,  .       T         .  ,    FIG.    27.       THREAD-LACE 

tion  of  the  wind  in  drawing  out     SCORLE  FROM  KILAUEA 

thread-like  pieces  from  the  jets 

of  lava  thrown  upwards  from  the  pool,  it  will  be  interest- 
ing if  its  true  cause  is  explained. 


186         VOLCANOES  AND  EARTHQUAKES 

Button,  in  his  report  on  the  Hawaiian  volcanoes, 
refers  to  the  formation  of  Pele's  hair  as  follows: 

"The  phenomenon  of  Pele's  hair  is  often  spoken  of 
in  the  school  books,  and  receives  its  name  from  this 
locality.  It  has  generally  been  explained  as  the  result 
of  the  action  of  the  wind  upon  minute  threads  of  lava 
drawn  out  by  the  spurting  up  of  boiling  lava.  Nothing 
of  the  sort  was  seen  here,  and  yet  Pele's  hair  was  seen 
forming  in  great  abundance.  Whenever  the  surface  of 
the  liquid  lava  was  exposed  during  the  break-up  the  air 
above  the  lake  was  filled  with  these  cobwebs,  but  there 
was  no  spurting  or  apparent  boiling  on  the  exposed 
surface.  The  explanation  of  the  phenomenon  which  I 
would  offer  is  as  follows:  Liquid  lava  coming  up  from 
the  depths  always  contains  more  or  less  water,  which 
it  gives  off  slowly  and  by  degrees,  in  much  the  same 
way  as  champagne  gives  off  carbonic  acid  when  the 
bottle  is  uncorked.  Water-vapor  is  held  in  the  liquid 
lava  by  some  affinity  similar  to  chemical  affinity,  and 
though  it  escapes  ultimately,  yet  it  is  surrendered  by 
the  lava  with  reluctance  so  long  as  the  lava  remains 
liquid.  But  when  the  lava  solidifies  the  water  is  expelled 
much  more  energetically,  and  the  water-vapor  separates 
in  the  form  of  minute  vesicles.  Since  the  congelation 
of  all  siliceous  compounds  is  a  passage  free  from  a  liquid 
condition  through  an  intermediate  state  of  viscosity  to 
final  solidity,  the  walls  of  these  vesicles  are  capable  of 
being  drawn  out  as  in  the  case  of  glass.  The  commotion 
set  up  by  the  descending  crust  produces  eddies  and 
numberless  currents  in  the  surface  of  the  lava.  These 
vesicles  are  drawn  out  on  the  surface  of  the  current 
with  exceeding  tenuity,  producing  myriads  of  minute 
filaments,  and  the  air,  agitated  by  the  intense  heat  at 
the  surface  of  the  pool,  readily  lifts  them  and  wafts 


SOME  FORMS  OF  LAVA  187 

them  away.  It  forms  almost  wholly  at  the  time  of  the 
break-up.  The  air  is  then  full  of  it.  Yet  I  saw  no  spout- 
ing or  sputtering,  but  only  the  eddying  of  the  lava  like 
water  in  the  wake  of  a  ship.  The  country  to  the  leeward 
of  Kilauea  shows  an  abundance  of  Pele's  hair,  and  it 
may  be  gathered  by  the  barrelful.  A  bunch  of  it  is 
much  like  finely  shredded  asbestos." 

You  have  probably  often  seen  the  beautiful  frost 
pictures  that  collect  on  the  panes  of  glass  in  a  room 
where  the  ventilation  has  been  neglected.  These  pictures 
consist  of  groupings  of  ice  crystals  that  collect  on  the 
surface  of  the  windows,  when  the  moist  vapor-laden  air 
in  the  room  is  chilled  by  contact  with  their  cold  surfaces. 
Now  the  crystals  formed  in  cooling  lavas  are  sometimes 
grouped  in  forms  closely  resembling  frost  pictures.  A 
few  of  such  forms  are  represented  in  Figs.  28  and  29  in 
lava  from  Mt.  Loa  and  Mt.  Kea. 

Certain   varieties   of   lava,    especially    that   which   is 


From  Dana's  Manual  of  Geology  From  Dana<s  Manual  of  Geology 

FIG.  28.     FROST-LIKE   LAVA  CRTS-      JTIG    29      FROST-LIKE  LAVA 
TALS  CRYSTALS 


found  in  dikes,  form  cool,  beautiful  columns  called  basaltic 
columns.  They  are  due  to  the  contraction  that  occurs 
on  the  cooling  of  the  material.  Instances  of  basaltic 


188         VOLCANOES  AND  EARTHQUAKES 

columns  are  seen  in  the  Giant's  Causeway,  on  the  northern 
coast  of  Ireland,  as  well  as  in  the  Isle  of  Cyclops  on  the 
coast  of  Italy.  The  general  appearance  of  the  latter 
is  represented  in  Fig.  30. 

It  is  a  curious  fact  that  the  entire  mass  of  basalt  does 


FIG.  30.     BASALTIC  COLUMNS,  ISLE  OF  CYCLOPS,  ITALY 


not  generally  take  the  columnous  form  but  only  certain 
layers  which  terminate  suddenly  above  and  below  at 
structureless  masses  of  basalt,  as  shown  in  Fig.  31. 
These  columns,  however,  are  always  found  at  right 
angles  to  the  cooling  surfaces  as  seen  in  the  figures. 
They  may,  therefore,  be  inclined  at  all  angles  to  the 
horizon. 


SOME  FORMS  OF  LAVA 


189 


When  molten  lava  is  only  thrown  up  a  short  distance 
into  the  air  from  a  crater  it  is  still  partially  molten 


FIG.  31.    COLUMNAR  AND  NON-COLUMNAR  BASALT 

when  on  falling  it  again  reaches  the  earth,  and  therefore 
clings  to  any  surface  on  which  it  falls.  There  are  thus 
built  up  curious  cones  known  as  driblet  cones,  in  which 
the  separate  drops  covering  the  sides  of  the  cone  can  be 
distinctly  traced.  Driblet  cones  are  represented  in 
Figs.  32  and  33.  Here,  as  can  be  seen,  the  separate 
drops  can  be  readily  traced  as  they  run  down  a  short 
distance  before  cooling. 

We  have  already  referred  briefly  to  the  lava  caves  or 
grottoes,  that  are  formed  in  some  of  the  lava  streams 
issuing  from  Vesuvius,  Etna,  or  Hawaii.  These  caves 


190         VOLCANOES  AND  EARTHQUAKES 

consist  either  of  a  number  of  communicating  huge  bubbles, 
or  of  the  tunnels  that  are  formed  in  the  lava  by  the 
hardening  of  the  outside  of  the  lava  streams  as  they  flow 
down  the  sides  of  the  mountain,  and  towards  the  close 
of  the  eruption  are  afterwards  emptied  by  the  molten 
lava  within  continuing  to  flow  to  a  lower  level  before 
solidifying.  Now,  in  the  interior  of  these  caves,  there 
are  often  found  on  the  walls,  as  well  as  on  the  portions 
of  the  floors  of  the  caves,  immediately  below  them, 
curious  pendants,  like  icicles,  or,  more  correctly,  like  the 
stalactites  oj  limestone  that  are  seen  hanging  to  the  walls 


From  Dana's  Manual  of  Geology 

FIGS.  32,  33.     DRIBLET  CONES 

of  caves  in  limestone  districts,  where  they  are  formed 
as  follows:  as  the  rain  water  sinks  through  limestone 
strata  it  dissolves  some  of  the  lime,  when,  slowly  fall- 
ing, drop  after  drop,  from  the  roofs  of  the  caverns,  small 
particles  of  lime  are  deposited  on  the  roof,  and  in  this 
manner  a  pendant  of  limestone  is  formed.  The  water 
that  falls  to  the  floor  of  the  causeway  immediately  below, 
also  builds  up  a  dome-like  hillock  called  a  stalagmite. 
In  due  time  the  pillar  reaches  downwards,  and  the  op- 
posite hillock  upwards  until  the  two  meet,  thus  forming 
great  natural  pillars  that  appear  to  hold  up  the  roof  of 


SOME  FORMS  OF  LAVA 


the  vast  cave  in  which  they  have 
been  slowly  formed.  A  number 
of  lava  stalactites  are  represented 
in  Fig.  34. 

Now,  in  a  similar  manner 
these  lava  stalactites,  formed  in 
the  lava  caves  or  grottoes,  are 
caused  by  the  stream  as  it  es- 
capes from  the  walls  of  the  caves 
depositing  on  them  stalactites 
of  various  lava  minerals  it  has 
dissolved  as  it  slowly  passed 
through  them. 

But  t-he  most  important  of  all 
volcanic  products  is  volcanic  dust. 
This,  as  we  have  seen,  is  so  light 
that  it  remains  longest  in  the  air, 
and  is  often  carried  by  the  winds 
to  great  distances  from  the  vol- 
cano from  which  it  escaped.  It 
may  interest  you  to  know  that 
some  of  the  most  fruitful  of  the 
great  wheat  fields  of  the  western 
parts  of  the  United  States  owe 
their  extraordinary  fertility  to 
immense  deposits  of  volcanic 
dust  that  have  been  thrown 
out  from  some  of  the  great  vol- 
canoes of  the  geological  past, 
now  found  in  an  extinct  con- 
dition in  these  parts  of  the  Uni- 
ted States. 

According  to  Russell,  immense 
deposits  of  volcanic  dust  are 
spread  over  vast  areas  in  Mon- 
tana, Southern  Dakota,  Ne- 
braska, and  Kansas,  as  well  as 
over  parts  of  Oregon,  and  Wash-  pIG.  34.  LAVA  STALACTITES 


From  Dana's  Man- 
ual of  Geology 


192         VOLCANOES  AND  EARTHQUAKES 

ington,  and,  indeed,   over  large   areas   of  southwestern 
Canada  and  Alaska. 

It  is  practically  certain  that  many  of  the  eruptions 
producing  this  dust  occurred  within  historic  times. 
There  must,  therefore,  have  been  many  times  in  these 
parts  of  our  country  when  the  dense  ash  clouds  hiding 
the  sun  turned  the  day  into  night  and  destroyed  the 
forests  and  other  vegetation  by  showers  of  red  hot  ashes. 
There  were  produced,  too,  the  same  great  dread,  and 
possibly  loss  of  life  as  common  during  historical  eruptions. 
It  is  pleasing,  however,  to  think  that  while  these  great 
catastrophes  brought  suffering  and  dread  to  the  people 
who  then  lived  on  the  earth,  they  were,  nevertheless, 
but  the  forerunners  of  those  fruitful  fields  that  at  a  much 
later  age  were  to  bless  the  people  who  afterwards  lived 
on  them. 


CHAPTER  XXI 

MUD  VOLCANOES  AND  HOT  SPRINGS 

Mud  volcanoes  are  the  more  or  less  conical  hillocks 
from  which,  under  certain  conditions,  mud  is  thrown 
out  through  the  crust  of  the  earth. 

Geikie  defines  mud  volcanoes  as  follows: 

"Conical  hills  formed  by  the  accumulation  of  fine 
and  usually  saline  (salty)  mud,  which,  with  various 
gases,  is  continuously  or  intermittently  given  out  from 
the  orifice  or  crater  in  the  centre.  They  occur  in  groups, 
each  hillock  being  sometimes  less  than  a  yard  in  height, 
but  ranging  up  to  elevations  of  100  feet  or  more.  Like 
true  volcanoes,  they  have  their  periods  of  repose,  when 
either  no  discharge  takes  place  at  all,  or  mud  oozes  out 
tranquilly  from  the  crater,  and  their  periods  of  ac- 
tivity, when  large  volumes  of  gas,  and  sometimes  columns 
of  flame,  rush  out  with  considerable  violence  and  ex- 
plosion, and  throw  up  mud  and  stones  to  a  height  of 
several  hundred  feet." 

There  are  two  kinds  of  mud  volcanoes:  those  in  which 
the  mud  is  thrown  out  by  the  action  of  different  kinds 
of  gases,  and  those  in  which  the  mud  is  thrown  out  by 
the  action  of  steam. 

Mud  volcanoes  may  or  not  be  volcanic  phenomena. 

Those   which   occur  in   the  neighborhood   of  volcanoes 

whether  active,   dormant,   or  extinct,   are  probably   of 

volcanic  origin.    There  are  others,  however,  which  occur 

M  [193] 


194         VOLCANOES  AND  EARTHQUAKES 

in  regions  far  removed  from  volcanoes.  These  are  prob- 
ably due  not  to  volcanoes,  but  to  chemical  action  and 
the  eruptions  are  caused  by  the  action  of  gases. 

The  gases  producing  these  eruptions  are  either  carbonic 
acid  gas  (the  gas  that  is  given  off  from  soda  water); 
carburetted  hydrogen  (the  gas  that  is  sometimes  seen 
escaping  from  the  bottom  of  marshy  ground) ;  sulphuretted 
hydrogen  (a  gas  that  is  given  off  from  rotten  or  decom- 
posing eggs,  and  possessing  the  characteristic  odor  of 
decayed  eggs)  and  nitrogen  gas  derived  from  the  at- 
mosphere. In  mud  volcanoes  of  the  gaseous  type  the 
mud  is  generally  cold,  and  the  water  salty.  In  this  latter 
case  the  mud  volcanoes  are  also  called  salses.  Daubeny 
has  pointed  out  that  the  mud  volcanoes  of  this  class  that 
occur  in  the  neighborhood  of  Sicily  are  due  to  the  slow 
burning  or  oxidation  of  beds  of  sulphur. 

Mud  volcanoes  which  eject  hot  mud  by  the  force  of 
eruption  of  steam,  which  occur  in  volcanic  districts, 
are  of  volcanic  origin.  They  are  caused  by  the  passage 
of  hot  water  and  steam  through  beds  of  volcanic  rock 
such  as  tufa,  or  hardened  volcanic  mud  and  other  vol- 
canic products.  The  hot  water  or  steam  raises  the 
temperature  of  the  mud  through  which  it  passes  to  the 
boiling  point.  As  Dana  remarks,  the  mud  varies  in  con- 
sistency from  very  liquid  muddy  water  to  a  thick  mass 
like  boiling  soap,  or  in  some  cases  like  masses  of  mud 
or  paint,  and,  in  still  other  cases,  to  material  like  soft 
mortar,  the  consistency  of  the  mud  varying  with  the 
dryness  of  the  season. 

There  are  three  regions  where  mud  volcanoes  are  es- 
pecially common.  One  of  the  best  known  is  in  the  Yellow- 
stone National  Park,  four  miles  north  of  Yellowstone 
Lake,  and  six  miles  from  Crater  Hill.  Some  of  these  mud 
volcanoes  have  circular  craters  about  ten  feet  in  depth 


MUD  VOLCANOES  AND  HOT  SPRINGS      195 

around  which  they  have  built  mounds,  the  rims  of  which 
are  several  feet  above  the  general  level. 

There  are  well-known  regions  of  mud  volcanoes  in 
different  parts  of  Iceland.  Here,  according  to  Lyell,  they 
occur  in  many  of  the  valleys  where  sulphur  vapor  and 
steam  bursts  from  fissures  in  the  ground  with  a  loud  hiss- 
ing noise.  In  these  regions  there  are  pools  of  boiling  water 
filled  with  a  bluish  black  clay-like  paste,  that  is  kept  vio- 
lently boiling.  Huge  bubbles,  fifteen  feet  or  more  in 
diameter,  rise  from  the  surface  of  the  boiling  mass.  The 
volcanoes  pile  up  the  mud  around  the  sides  of  their  craters 
or  basins. 

Another  part  of  the  world  where  mud  volcanoes  are 
especially  numerous  is  on  the  western  shores  of  the  Cas- 
pian Sea  at  a  place  called  Baku.  These  are  of  the  gaseous 
type  and  are  attended  by  flames  that  blaze  up  to  great 
heights  often  for  several  hours.  These  flames  are  due  to 
the  presence  of  natural  gas  and  petroleum  vapor  that 
pass  out  through  the  water.  Large  quantities  of  mud  are 
thrown  out  from  the  craters  of  these  mud  volcanoes. 

There  are  also  many  mud  volcanoes  in  a  district  in 
India  about  120  miles  northwest  of  Cutch  near  the  mouth 
of  the  Indus.  In  this  region  the  cone  built  up  around  the 
crater  is  sometimes  as  high  as  400  feet. 

The  following  description  of  mud  volcanoes  on  Java 
is  quoted  from  Daubeny's  book  on  volcanoes. 

"  It  would  appear  likewise  from  Dr.  Horsfield's  descrip- 
tion, that  Java  exhibits  phenomena  of  a  similar  kind  to 
those  noticed  in  Sicily  and  at  the  foot  of  the  Apennines, 
and  there  known  under  the  name  of  'Salses.'  In  the 
calcareous  district  (which  I  suspect  to  belong  to  the  same 
class  of  formations  as  the  blue  clay  and  tertiary  limestone 
of  Sicily)  occur  a  number  of  hot  springs,  containing  in 
solution  a  large  quantity  of  calcareous  earth,  which  in- 


196         VOLCANOES  AND  EARTHQUAKES 

crusts  the  surface  of  the  ground  near  it.  Of  these,  some 
are  much  mixed  with  petroleum,  and  others  highly  saline. 

"The  latter  are  dispersed  through  a  district  of  country 
consisting  of  limestone,  several  miles  in  circumference. 
They  are  of  considerable  number,  and  force  themselves 
upwards  through  apertures  in  the  rocks  with  some  vio- 
lence and  ebullition.  The  waters  are  strongly  impreg- 
nated with  muriate  of  soda,  and  yield  upon  evaporation 
very  good  salt  for  culinary  purposes  (not  less  than  200 
tons  in  the  year). 

"About  the  centre  of  this  limestone  district  is  found  an 
extraordinary  volcanic  phenomenon.  On  approaching  the 
spot  from  a  distance,  it  is  first  discovered  by  a  large  vol- 
ume of  smoke  rising  and  disappearing  at  intervals  of  a 
few  seconds,  resembling  the  vapors  arising  from  a  violent 
surf,  whilst  a  dull  noise  is  heard  like  that  of  distant  thun- 
der. Having  advanced  so  near  that  the  vision  was  no 
longer  impeded  by  the  smoke,  a  large  hemispherical  mass 
was  observed,  consisting  of  black  earth  mixed  with  water, 
about  sixteen  feet  in  diameter,  rising  to  the  height  of 
twenty  or  thirty  feet  in  a  perfectly  regular  manner,  and, 
as  it  were,  pushed  up  by  a  force  beneath,  which  suddenly 
exploded  with  a  dull  noise,  and  scattered  about  a  volume 
of  black  mud  in  every  direction.  After  an  interval  of  two 
or  three,  or  sometimes  four  or  five  seconds,  the  hemi- 
spherical body  of  mud  or  earth  rose  and  exploded  again. 

"In  the  same  manner  this  volcanic  ebullition  goes  on 
without  interruption,  throwing  up  a  globular  mass  of 
mud,  and  dispersing  it  with  violence  through  the  neigh- 
boring places.  The  spot  where  the  ebullition  occurs  is 
nearly  circular  and  perfectly  level;  it  is  covered  with  only 
the  earthy  particles  impregnated  with  salt  water,  which 
are  thrown  up  from  below;  its  circumference  may  be  esti- 
mated at  about  half  an  English  mile.  In  order  to  conduct 


MUD  VOLCANOES  AND  HOT  SPRINGS      197 

the  salt  water  to  the  circumference,  small  passages  or 
gutters  are  made  in  the  loose  muddy  earth,  which  lead 
it  to  the  borders,  where  it  is  collected  in  holes  dug  in  the 
ground  for  the  purpose  of  evaporation. 

"A  strong,  pungent,  sulphurous  smell,  somewhat  re- 
sembling that  of  earth-oil  (naphtha),  is  perceived  on 
standing  near  the  site  of  the  explosion,  and  the  mud 
recently  thrown  up  possesses  a  degree  of  heat  greater  than 
that  of  the  surrounding  atmosphere.  During  the  rainy 
season  these  explosions  are  more  violent,  the  mud  is 
thrown  up  much  higher,  and  the  noise  is  heard  at  a  greater 
distance. 

"This  volcanic  phenomenon  is  situated  near  the  centre 
of  the  large  plain,  which  interrupts  the  great  series  of 
volcanoes,  and  owes  its  origin  to  the  same  general  cause 
as  that  of  the  numerous  eruptions  met  with  in  this  island." 

There  are,  in  many  parts  of  the  world,  springs,  whose 
waters  issue  from  their  reservoirs  at  temperatures  either 
at  or  near  the  boiling  point  of  water.  These  are  called 
hot  or  thermal  springs.  Hot  springs  are  found  both  in 
volcanic  regions,  as  well  as  in  regions  where  there  are  no 
volcanoes,  but  where  there  are  lines  of  deep  fissures  or 
faults.  According  to  Dana,  in  both  of  these  classes,  the 
cause  is  to  be  traced  to  heat  of  volcanic  or  deep  subter- 
ranean origin.  Hot  springs  are  also  found  in  regions  where 
there  are  no  volcanoes.  In  these  cases  the  heat  is  due  to 
the  gradual  oxidation  of  various  sulphide  ores,  or  to  some 
other  chemical  action. 

The  waters  of  hot  or  thermal  springs  almost  always 
contain  various  mineral  substances  in  solution.  All 
spring  water  contains  some  little  dissolved  mineral  matter, 
but  in  hot  springs  the  quantity  of  this  matter  is  greater 
than  in  cold  springs,  because  hot  water  can  dissolve 
mineral  substances  much  better  than  can  cold  water. 


198         VOLCANOES  AND  EARTHQUAKES 

It  might  surprise  you  to  hear  that  one  of  the  commonest 
substances  that  is  found  in  solution  in  the  waters  of  many 
hot  springs  is  silica;  for  silica  is  practically  sand,  and 
sand  does  not  easily  dissolve  in  water  as  does  sugar. 
The  very  hot  water,  however,  which  comes  from  the  hot 
spring,  whose  temperature  below  the  earth's  surface  is 
very  much  higher  than  it  is  when  it  comes  out  of  the 
spring,  possesses  the  power  of  readily  dissolving  silica 
from  the  rocks  over  which  it  flows.  When  the  waters  of 
such  springs  reach  the  surface  the  silica  is  deposited  in  a 
solid  condition  around  the  outlets  of  the  springs.  In  this 
way  there  are  built  up  craters  or  mounds,  or,  more  cor- 
rectly, crater-shaped  basins. 

Sometimes  the  hot  water  contains  calcareous  substances 
dissolved  in  it,  the  solution  being  caused  not  only  by  reason 
of  the  hot  water,  but  also  by  means  of  the  carbonic  gas  it 
contains.  When  this  water  flows  from  the  springs,  it 
builds  up  the  same  crater-shaped  mounds,  only  in  this 
case  the  mounds  are  of  lime  instead  of  silica. 

There  are  peculiar  kinds  of  hot  springs  called  geysers, 
that  possess  the  power  of  throwing  huge  streams  of  water 
up  into  the  air  at  more  or  less  regular  intervals.  The 
word  geyser  is  an  Icelandic  word  meaning  to  rage,  or 
snort,  or  gush,  the  name  being  given  by  reason  of  the  man- 
ner in  which  the  waters  rush  violently  out  during  an  erup- 
tion. 

As  Dana  points  out,  when  the  water  in  a  basin  of  a  hot 
spring  merely  boils,  whether  this  boiling  is  nearly  con- 
tinuous, or  the  water  is  alternately  boiling  and  quiet,  the 
spring  is  called  a  hot  or  thermal  spring,  but  where  the 
water  is  thrown  violently  out  at  more  or  less  regular  in- 
tervals, it  is  called  a  geyser. 

The  cause  of  the  eruption  of  a  geyser  was  discovered  by 
Professor  Bunsen,  the  celebrated  German  chemist,  after 


MUD  VOLCANOES  AND  HOT  SPRINGS      199 

a  careful  study  of  the  geyser  regions  in  Iceland.  The 
waters  of  geysers  contain  large  quantities  of  either  silica 
or  lime  in  solution.  Bunsen  traced  the  cause  of  these 
curious  eruptions  to  be  the  manner  in  which  the  hot 
springs  pile  up  cones  of  silica  or  limestone  around  their 
mouths. 

The  water  of  a  geyser  generally  issues  from  the  top  of  a 
more  or  less  conical  hillock,  reaching  the  surface  through 
a  funnel-shaped  tube.  Both  the  tube  and  the  basin  are 
covered  with  a  smooth  coating  of  silica  or  limestone.  In 
the  case  of  the  Great  Geyser  in  Iceland,  the  basin  is  over 
fifty  feet  high  and  seventy-five  feet  deep.  Both  the  tube 
and  the  basin  have  been  slowly  deposited  by  the  hot 
water  of  the  geyser. 

It  is  only  when  the  tube  of  a  geyser  has  reached  a  certain 
depth  that  the  geyser  is  able  to  erupt.  Moreover,  as  soon 
as  this  tube  passes  a  certain  depth  the  geyser  can  no  longer 
erupt  and  forever  afterwards  becomes  an  ordinary  hot 
spring.  There  are,  therefore,  to  be  found  in  most  geyser 
regions,  a  number  of  what  might  be  called  young  geysers 
or  merely  hot  springs,  that  are  not  yet  deep  enough  to 
erupt;  others  that  have  just  commenced  eruption,  others 
that  have  reached  their  prime,  while  others  that,  old  and 
decrepit,  have  again  merely  become  hot  springs. 

Let  us  now  try  to  understand  the  cause  of  the  eruption 
of  a  geyser.  Bunsen's  explanation,  which  is  now  generally 
accepted,  is  as  follows: 

The  heat  of  the  volcanic  strata  through  which  the  tube 
of  the  geyser  extends,  gradually  raises  the  temperature 
of  the  water  that  fills  the  geyser  tube.  Since  the  boiling 
point  of  a  liquid  increases  with  the  pressure  to  which  it 
is  subjected,  far  down  in  the  tube  of  a  geyser,  the  pressure 
arising  from  the  weight  of  the  water  above  it  is  sufficiently 
great  to  prevent  the  water  from  beginning  to  boil  until 


200          VOLCANOES  AND  EARTHQUAKES 

it  reaches  a  temperature  far  higher  than  that  at  which  it 
would  boil  in  the  upper  parts  of  the  tube.  Suppose  now, 
when  the  water  in  the  funnel-shaped  tube  is  nearly  filled 
to  the  top,  the  water  at  last  grows  hot  enough  to  begin 
boiling  at  some  point  near  the  middle  of  the  tube.  The 
pressure  of  the  steam  driven  off  from  this  portion  of  the 
water  raises  the  column  of  water  above  it  in  the  tube 
and  begins  to  empty  it  out  of  the  top  of  the  geyser.  All 
the  water  below  this  point  being  thus  suddenly  relieved 
of  its  pressure,  and  being  now  much  hotter  than  is  neces- 
sary to  boil  the  water  at  that  decreased  pressure,  suddenly 
flashes  into  steam,  and  violently  shoots  out  all  the  water 
above  it  to  a  height  that  in  some  cases  may  be  as  great 
as  100  to  200  feet.  The  steam  causes  this  eruption,  then 
rushes  out  with  a  roar,  and  the  geyser  eruption  is  over. 

Professor  Tyndall  in  his  charming  book  entitled  "Heat 
as  a  Mode  of  Motion"  speaks  as  follows  concerning  Pro- 
fessor Bunsen's  discovery: 

"  Previous  to  an  eruption,  both  the  tube  and  basin  are 
filled  with  hot  water;  detonations  which  shake  the  ground, 
are  heard  at  intervals,  and  each  is  succeeded  by  a  violent 
agitation  of  the  water  in  the  basin.  The  water  in  the  pipe 
is  lifted  up  so  as  to  form  an  eminence  in  the  middle  of  the 
basin,  and  an  overflow  is  the  consequence.  These  detona- 
tions are  evidently  due  to  the  production  of  steam  in  the 
ducts  which  feed  the  geyser  tube,  which  steam  escaping 
into  the  cooler  water  of  the  tube  is  there  suddenly  con- 
densed, and  produces  the  explosions.  Professor  Bunsen 
succeeded  in  determining  the  temperature  of  the  geyser 
tube,  from  top  to  bottom,  a  few  minutes  before  a  great 
eruption;  and  these  observations  revealed  the  extraor- 
dinary fact  that  at  no  part  of  the  tube  did  the  water  reach 
its  boiling  point.  In  the  sketch  [not  reproduced]  I  have 
given  on  one  side  the  temperatures  actually  observed, 


MUD  VOLCANOES  AND  HOT  SPRINGS     201 

and  on  the  other  side  the  temperatures  at  which  water 
would  boil,  taking  into  account  both  the  pressure  of  the 
atmosphere  and  the  pressure  of  the  superincumbent 
column  of  water.  The  nearest  approach  to  the  boiling 
point  is  at  A,  a  height  of  30  feet  from  the  bottom;  but  even 
here  the  water  is  2°  C.,  or  more  than  3£°  F.,  below  the 
temperature  at  which  it  could  boil.  How  then  is  it  pos- 
sible that  an  eruption  could  occur  under  such  circum- 
stances? 

"Fix  your  attention  upon  the  water  at  the  point  A, 
where  the  temperature  is  within  2°  C.  of  the  boiling  point. 
Call  to  mind  the  lifting  of  the  column  when  the  detona- 
tions are  heard.  Let  us  suppose  that  by  the  entrance  of 
steam  from  the  ducts  near  the  bottom  of  the  tube,  the 
geyser  column  is  elevated  six  feet,  a  height  quite  within 
the  limits  of  actual  observation;  the  water  at  A  is  thereby 
transferred  to  B.  Its  boiling  point  at  A  is  123.8°,  and  its 
actual  temperature  121.8°;  but  at  B  its  boiling  point  is 
only  120.8°,  hence,  when  transferred  from  A  to  B  the  heat 
which  it  possesses  is  in  excess  of  that  necessary  to  make 
it  boil.  This  excess  of  heat  is  instantly  applied  to  the 
generation  of  steam:  the  column  is  thus  lifted  higher, 
and  the  water  below  is  further  relieved.  More  steam  is 
generated;  from  the  middle  downwards  the  mass  suddenly 
bursts  into  ebullition,  the  water  above,  mixed  with  steam 
clouds,  is  projected  into  the  atmosphere,  and  we  have  the 
geyser  eruption  in  all  its  grandeur. 

"By  its  contact  with  the  air  the  water  is  cooled,  falls 
back  into  the  basin,  partially  refills  the  tube,  in  which  it 
gradually  rises,  and  finally  fills  the  basin  as  before.  De- 
tonations are  heard  at  intervals,  and  risings  of  the  water 
in  the  basin.  These  are  so  many  futile  attempts  at  an 
eruption,  for  not  until  the  water  in  the  tube  comes 
sufficiently  near  its  boiling  temperature,  to  make  the 


202          VOLCANOES  AND  EARTHQUAKES 

lifting  of  the  column  effective,  can  we  have  a  true  erup- 
tion." 

The  principal  geyser  regions  of  the  world  are  in  Iceland, 
in  New  Zealand,  and  in  the  Yellowstone  National  Park 
in  the  United  States. 

There  are  several  geyser  regions  in  Iceland.  The  best 
known  lies  in  the  neighborhood  of  Mt.  Hecla.  Here  is  a 
great  geyser  that  shoots  up  a  column  of  water  to  a  height 
of  about  100  feet  every  thirty  hours.  Fig.  35  repre- 
sents the  appearance  of  the  crater  of  the  great  geyser 
in  Iceland. 

It  is  a  well-known  fact  that  in  geyser  regions  generally, 


FIG.  35.    CRATER  OF  THE  GREAT  GEYSER  OP  ICELAND 

the  throwing  of  stones  or  other  materials  into  the  tube 
will  frequently  hasten  an  eruption.  This  is  probably  due 
to  the  fact  that  the  throwing  in  of  these  things  results  in 
the  raising  of  the  water  in  the  tube,  thus  hastening  the 
eruption. 


MUD  VOLCANOES  AND  HOT  SPRINGS     203 

The  New  Zealand  region  is  in  the  neighborhood  of 
Lake  Rotomahama  in  the  northern  island. 

The  geyser  region  in  the  Yellowstone  Park  is  by  far 
the  most  interesting  of  all  geyser  regions.  This  region  is 
situated  principally  around  Fire-Hole  Fork  of  the  Madison, 
and  near  Shoshone  Lake  at  the  head  of  Lake  Fork  of  the 
Snake  River.  There  are  many  geysers  in  this  region,  as 
well  as  simple  hot  springs.  The  temperature  of  their 
waters  varies  from  between  160°  and  200°  F.  to  the 
boiling  point  of  water  at  this  elevation.  As  you  are 
probably  aware,  water  boils  at  the  temperature  of  212°  F. 
only  under  the  condition  of  the  ordinary  atmospheric 
pressure  that  exists  at  the  level  of  the  sea.  At  higher 
elevations,  such  as  on  the  slopes  of  mountains,  or  on  high 
plateaus,  water  boils  at  a  lower  temperature.  The  height 
of  the  country  in  which  the  Yellowstone  Park  is  situated 
is  so  great  that  the  water  boils  at  temperatures  of  from 
198°  to  199°  F. 

The  conical  hillock  of  geyser  cones  from  which  the 
waters  flow  assume  various  shapes,  two  of  which  are 
shown  in  Figs.  36  and  37. 

That  shown  in  Fig.  36  represents  the  shape  of  the  cone 


From  Dana's  Manual  of  Geology 

FIG.  36.  GIANT  GEYSER  FIG.  37.  BEE  HIVE 

of  the  giant  geyser  in  the  upper  geyser  basin  of  the  Fire- 
Hole,  Yellowstone  National  Park.  This  cone  is  about 
ten  feet  in  height,  and  twenty-four  feet  in  diameter.  As 
shown  in  the  figure  it  is  broken  on  one  of  its  sides.  It 


204         VOLCANOES  AND  EARTHQUAKES 

throws  out,  at  long  intervals,  a  column  of  water  the  height 
of  which  varies  from  ninety  to  200  feet. 

Fig.  38  represents  the  crater  of  a  cone  known  as  the 
Bee  Hive  in  eruption. 

Besides  the  above  named  geyser  regions  there  is  an- 
other region  on  the  shores  of  Celebes,  and  a  small  region  on 
San  Miguel,  in  the  Azores  Islands,  in  the  Atlantic  Ocean. 

Besides  hot  springs  and  mud  volcanoes  there  are  two 
other  phenomena  connected  with  volcanic  action  that  we 
will  now  briefly  describe. 

When  eruptions  take  place  and  the  lava  begins  to  flow 
down  the  side  of  a  mountain,  the  different  vapors  and  gases 
with  which  the  lava  is  charged  begin  to  escape  or  pass  out 
from  the  boiling  or  fused  mass.  When  these  substances 
are  of  such  a  character  that  they  produce  fumes,  or  the 
vapors  of  various  chemical  substances,  that  become  solid 
on  cooling,  they  form  what  are  called  fumaroles,  a  word 
derived  from  a  Latin  word  meaning  "  to  smoke."  For  the 
greater  part,  fumaroles  are  found  on  the  edge  of  craters,  but 
sometimes  are  found  in  cavernous  places  either  in  the  cra- 
ter or  in  the  lava  streams. 

There  is,  still,  another  class  of  openings  through  which 
only  sulphurous  vapors  escape.  These  are  called  sol- 
fataras,  a  word  derived  from  the  Italian  word  solfo,  or 
sulphur.  Solfataras  are  generally  found  in  regions  dis- 
tant from  volcanic  action.  In  the  materials  that  escape 
from  recently  ejected  lava,  or  molten  lava,  the  tempera- 
ture is  high  enough  to  volatilize  many  of  the  solid  ingre- 
dients. But  where  the  temperature  is  low,  only  sulphur 
vapors  are  driven  off.  It  is  for  this  reason  that  fumaroles 
are  only  found  around  the  craters  of  active  volcanoes,  or 
on  the  lines  of  cracks  or  crevices  of  the  lava  stream  where 
the  temperature  is  very  high. 

Besides  water  vapor  and  sulphurous  vapors  there  are 


MUD  VOLCANOES  AND  HOT  SPRINGS      205 


From  Dana's  Manual  of  Geology 

FIG.  38.    BEE  HIVE  GEYSER  OF  ICELAND 


206          VOLCANOES  AND  EARTHQUAKES 

other  substances  that  escape  from  the  earth  in  volcanic 
districts.  Sulphurous  acid,  together  with  hydrogen  and 
nitrogen  escape  from  nearly  all  lava.  At  Vesuvius  chlo- 
rine gas  is  given  off.  This,  however,  as  soon  as  it  passes 
into  the  atmosphere  becomes  changed  into  hydrochloric 
acid.  Sulphurous  acid  is  frequently  changed  into  sul- 
phuric acid,  which,  combining  with  various  substances, 
forms  such  materials  as  gypsum,  or  sulphate  of  lime,  the 
chemical  name  for  plaster  of  Paris;  sulphate  of  soda  or 
Glauber's  salt;  sodium  chloride  or  common  table  salt;  and 
sal  ammoniac.  You  will  remember  in  reading  the  de- 
scription of  Vulcano,  in  the  Grecian  Archipelago,  that 
some  of  these  products  were  collected  at  the  chemical 
works  that  had  been  established  on  the  volcano. 

When  a  volcanic  mountain  is  for  the  time  being  passing 
from  an  active  to  an  extinct  condition,  it  is  sometimes  said 
to  be  in  the  fumarole  stage,  since  the  presence  of  the  fuma- 
roles  are  the  only  indication  of  its  activity.  The  volcanic 
heat  is  still  great.  When  it  reaches  a  still  greater  decline, 
the  fumaroles  disappear,  and  only  solfataras  are  left. 
The  amount  of  heat  is  now  only  sufficient  to  produce 
sulphur  vapors  and  the  vapor  of  water.  This  is  called 
the  solfatara  stage. 

Of  course,  as  we  have  already  pointed  out,  fumaroles 
and  solfataras  may  occur  in  the  neighborhood  of  a  volcano 
at  different  distances  from  its  crater. 


CHAPTER  XXII 

THE  VOLCANOES  OF  THE  MOON 

There  can  be  no  doubt  that  the  moon  was  once  the  seat 
of  very  great  volcanic  activity.  It  was  formerly  believed 
that  the  very  many  volcanic  craters  which  can  be  seen  on 
its  surface  when  it  is  examined  by  a  comparatively  small 
telescope,  were  all  extinct.  While  this  is  nearly  true,  yet 
recent  investigations  have  shown  that  in  all  probability 
a  feeble  volcanic  activity  still  exists  in  a  few  of  these 
craters. 

The  distinctness  with  which  the  surface  of  the  moon 
is  seen  does  not  depend  so  much  on  the  size  of  the  tele- 
scope employed,  as  it  does  on  the  steadiness  of  the  atmos- 
phere when  the  telescope  is  being  used.  When  one  wishes 
to  examine  a  very  distant  body  like  a  star,  it  is  necessary 
to  use  a  powerful  telescope,  but  in  the  case  of  a  compara- 
tively near  body,  like  one  of  the  planets  or  the  moon,  a 
big  telescope  is  not  necessary.  It  is,  however,  necessary 
to  make  the  observations  at  some  time  of  the  year,  or 
in  some  part  of  the  world,  when  the  air  is  apt  to  be  free 
from  winds. 

A  person  on  the  earth's  surface  looking  at  the  heavenly 
bodies  through  a  telescope  is  practically  in  the  position 
in  which  he  would  be  were  he  at  the  bottom  of  the  water 
in  a  large  lake  looking  up  through  the  water  at  some  body 
in  the  heavens.  He  would  have  no  difficulty  in  seeing  such 
a  body  distinctly  as  long  as  the  upper  surface  of  the  water 
remained  quiet,  and  unruffled  by  waves.  As  soon,  how- 
[207] 


208         VOLCANOES  AND  EARTHQUAKES 

ever,  as  waves  were  set  up,  the  images  seen  in  the  tele- 
scope are  so  distorted  as  to  become  practically  worthless. 
It  is  for  this  reason  that  it  is  customary  to  build  great 
astronomical  observatories  in  parts  of  the  world  where 
there  are  apt  to  be  many  days  in  the  year  when  the  air 
is  almost  entirely  free  from  wind. 

Since  the  atmosphere  is  apt  to  be  disturbed  by  winds  in 
both  the  temperate  and  the  polar  latitudes,  these  parts  of 
the  world  are  not  very  satisfactory  as  sites  for  astronomi- 
cal observatories.  The  conditions  are  more  favorable 
near  the  equator,  since,  although  at  certain  seasons  of 
the  year  there  are  very  severe  storms  in  these  regions, 
yet  there  are  quite  long  periods  when  the  air  is  almost 
entirely  free  from  winds. 

It  is  for  this  reason  that  Harvard  University  has  erected 
an  astronomical  observatory  at  Arequipa,  Peru,  at  an 
elevation  of  8,000  feet  above  the  level  of  the  Pacific 
Ocean.  Here,  with  a  comparatively  small  object  glass, 
of  about  twelve  inches  aperture,  magnificent  photographs 
have  been  obtained  not  only  of  the  moon  but  also  of  the 
planet  Mars. 

According  to  Professor  Pickering,  from  whose  magnifi- 
cent work,  entitled,  "The  Moon,"  much  of  the  informa- 
tion in  this  chapter  has  been  obtained,  the  moon,  which 
is  generally  spoken  of  as  a  satellite  of  the  earth,  ought 
rather  to  be  called  the  earth's  twin  planet.  Although  the 
moon  appears  to  revolve  in  a  small  elliptical  orbit  around 
the  earth  it  should  properly  be  said  to  revolve  around 
the  sun;  for,  together  with  the  earth,  it  revolves  around 
the  sun  once  every  year.  As  seen  from  any  of  the  planets 
that  lie  near  the  earth  the  earth  and  moon  would  appear 
as  a  very  beautiful  double  star. 

In  order  the  more  readily  to  understand  what  will  be 
said  shortly  concerning  the  origin  of  the  moon,  it  may  be 


VOLCANOES  OF  THE  MOON  209 

mentioned  that  the  moon's  diameter  is  2,163  miles,  or  a 
little  more  than  one-fourth  the  diameter  of  our  earth. 

You  will,  most  probably,  be  surprised  to  learn  that 
the  origin  of  the  moon  is  believed  to  be  very  different 
from  the  origin  of  the  moons  or  satellites  of  Jupiter,  Saturn, 
and  the  other  planets.  As  we  have  already  seen,  accord- 
ing to  the  nebular  hypothesis,  all  the  planets  except  the 
earth  probably  had  their  moons  formed  from  the  rings 
that  were  left  surrounding  them  when  they  shrunk  on 
cooling  to  their  present  dimensions.  Such  a  ring  is  still 
to  be  seen  surrounding  Saturn. 

Now  it  is  believed  that  our  moon  was  formed  in  a  dif- 
ferent manner.  It  was  not  thrown  off  from  the  earth 
while  the  latter  was  in  a  highly  fluid  or  gaseous  condition, 
but  after  the  earth  had  shrunken  to  nearly  its  present 
size  and,  most  probably,  after  a  solid  crust  had  been  formed 
on  its  surface.  In  order  that  our  earth  should  be  able  to 
violently  throw  off  a  large  portion  of  its  mass,  it  is  only 
necessary  that  at  the  time  this  separation  occurred,  its 
motion  of  rotation  on  its  axis  was  sufficiently  great  to 
enable  it  to  make  one  complete  revolution  in  rather  less 
than  three  hours  instead  of  in  the  twenty-four  hours  it 
now  requires.  At  this  velocity  of  rotation,  objects  would 
fly  off  the  earth  in  the  neighborhood  of  the  equator,  under 
the  influence  of  the  high  centrifugal  force.  Let  us,  then, 
endeavor  to  see  if  it  was  at  all  probable  that  the  earth 
ever  did  turn  so  rapidly  on  its  axis. 

You  all  probably  know  that  it  is  principally  the  attrac- 
tion of  the  moon  that  produces  the  earth's  tides.  Of 
course,  the  sun  also  produces  tides  on  the  earth,  but  it  is 
so  far  off  from  the  earth  that  not  withstanding  its  greater 
mass  the  tides  it  forms  are  much  smaller  than  those  pro- 
duced by  the  moon.  You  also  know  that  the  moon  pro- 
duces at  the  same  time  two  tides  in  every  twenty-four 

N 


210         VOLCANOES  AND  EARTHQUAKES 

hours,  on  directly  opposite  sides  of  the  earth;  one  on  the 
side  immediately  under  the  moon,  and  the  other  on  the 
side  furthest  from  the  moon.  As  the  earth  rotates  between 
these  two  tides,  they  act  as  a  break  which  serves  to  impede 
its  motion.  Every  high  tide,  therefore,  tends  to  make 
the  earth  rotate  more  slowly,  and  thus  to  slowly  increase 
the  length  of  the  day.  For  this  reason  to-day  is  a  trifle 
longer  than  yesterday,  and  still  longer  than  a  day  a  hun- 
dred years  ago. 

You  must  not  suppose  for  a  moment  that  this  increase 
in  the  length  of  the  day  is  large.  On  the  contrary,  it  is  so 
small  that  since  the  year  A.  D.  1,  up  to  the  present  time, 
the  day  is  only  a  very  small  fraction  of  a  second  longer. 

But  it  was  very  different  in  the  earth's  geological  past, 
when  the  inside  of  the  earth  was  in  a  molten  condition; 
for  then  great  tides  were  set  up  in  the  melted  interior  of 
the  earth  that  not  only  greatly  changed  the  shape  of  the 
earth,  but  decreased  the  rate  of  rotation  much  more 
rapidly  than  it  does  when  the  earth's  tides  are  limited 
as  they  are  now  to  the  waters  on  the  earth's  surfaces. 

There  was,  however,  at  the  same  time,  something  going 
on  that  tended  greatly  to  make  the  earth  turn  more 
rapidly  on  its  axis.  While  the  originally  melted  earth 
was  cooling  and  shrinking,  the  rate  of  its  rotation  was 
necessarily  increasing.  As  you  know,  the  time  of  vibra- 
tion of  a  pendulum,  that  is,  the  time  it  requires  to  make 
one  complete  to-and-fro  motion,  is  shorter  the  shorter 
the  length  of  the  pendulum.  A  pendulum  two  feet  long 
moves  to  and  fro  more  slowly  than  a  pendulum  one  foot 
in  length.  In  the  same  way  a  rotating  sphere  will  make 
one  complete  rotation  in  a  shorter  time  when  its  radius, 
which  corresponds  to  the  length  of  a  pendulum,  is  shorter. 
Therefore,  as  the  earth  shrunk,  it  rotated  more  and  more 
rapidly,  and  at  last  reached  a  rapidity  of  motion  at  which 


VOLCANOES  OF  THE  MOON  211 

an  immense  quantity  of  matter  flew  off  its  surface  nearest 
the  equator  and  went  out  into  space,  never  again  to  re- 
turn. It  was  this  mass  that  constituted  the  earth's  moon. 

Necessarily  such  a  tremendous  catastrophe  was  at- 
tended by  an  earthquake  as  well  as  by  the  most  fearful 
volcanic  phenomena  that  the  earth  has  ever  witnessed. 
The  terrible  catastrophe  produced  by  the  explosive 
eruption  of  Krakatoa  was  but  as  a  small  drop  of  rain 
falling  on  the  earth,  when  compared  with  the  catastrophe 
produced  when  the  "five  thousand  million  cubic  miles 
of  material  left  the  earth's  surface,  never  again  to  return 
to  it." 

It  is  not  known  whether  this  matter  was  torn  off  the 
earth  at  a  single  time  or  during  successive  times,  but 
quoting  the  beautiful  language  of  Professor  Pickering: 

"We  may  try  in  vain  to  imagine  the  awful  uproar  and 
fearful  volcanic  phenomena  exhibited  when  a  planet  was 
cleft  in  twain,  and  a  new  planet  was  born  into  the  solar 
system." 

This  terrible  catastrophe  took  place  at  a  time  not  when 
the  earth  was  a  gaseous  mass,  but  when  it  had  condensed 
into  a  comparatively  small  mass  not  much  larger  than  it 
is  at  its  present  time,  and  possibly  even  after  it  had  har- 
dened sufficiently  to  form  a  solid  crust  on  its  outside. 

If  you  look  at  a  map  of  the  earth  on  a  M  creator's  projec- 
tion, such,  for  example,  as  that  employed  in  illustrating 
the  distribution  of  the  world's  volcanoes  in  Fig.  24,  you 
can  see,  even  without  any  very  close  examination,  that 
the  great  water  area  of  the  Atlantic  Ocean  has  its  eastern 
and  western  shores  almost  parallel  to  each  other,  so  that  if 
you  conceive  the  Eastern  and  Western  Continents  as 
being  pushed  together,  they  would,  except  at  the  south, 
almost  completely  fit  together,  and  the  same  thing  is  true, 
if  Greenland  is  pushed  towards  the  northeastern  coast  of 


212         VOLCANOES  AND  EARTHQUAKES 

North  America.  Of  course,  some  portions  of  the  coast 
would  not  fit  exactly,  but  then  these  portions  might 
either  have  been  worn  away,  or,  as  is  more  probable,  have 
been  changed  in  shape  by  the  deposit  of  immense  beds  of 
sedimentary  rocks  spread  over  the  borders  of  the  Atlantic 
by  the  great  rivers  that  empty  into  it.  This  is  so  remark- 
able a  fact  that  it  will  be  well  worth  your  while  to  turn  to 
the  map  mentioned  and  convince  yourself  of  the  proof 
of  what  I  have  just  said.  As  you  will  see,  Europe  and 
Africa  would  almost  exactly  fit  against  South  America 
and  North  America,  while  Greenland  would  even  more 
closely  fit  against  the  northeastern  coast  of  North  America. 

Now,  while  we  do  not  say  that  it  was  so,  it  has  been 
suggested  as  just  possible  that  the  great  depression  of 
the  Pacific  Ocean  represents  the  spot  that  was  once  filled 
by  the  moon.  That  the  Eastern  and  Western  Continents, 
then  torn  asunder  by  the  great  force  of  the  convulsion, 
were  left  floating  on  the  surface  of  a  sea  of  molten  matter, 
a  greatly  widened  crack  marking  positions  they  assumed 
at  the  end  of  this  cataclysm. 

Of  course,  you  must  understand  that  all  this  is  a  mere 
supposition,  and  that  we  do  not  know  whether  the  earth 
was  actually  cooled  on  the  outside  when  this  occurred, 
since  it  might  have  still  been  in  a  liquid  condition  through- 
out. It  would  seem,  however,  to  have  occurred  rather 
recently,  since  it  could  not  have  occurred  until  the  earth 
shrunk  so  much  that  it  became  so  small  in  radius  as  to 
acquire  a  very  rapid  rate  of  motion  on  its  axis. 

It  is  an  interesting  fact  that  we  are,  perhaps,  better 
acquainted  with  that  side  of  the  moon  which  is  turned 
towards  us  than  we  are  with  the  surface  of  the  earth  on 
which  we  live.  Of  course,  I  do  not  mean  in  the  small 
details  of  the  moon's  surface,  but  with  such  portions  as 
can  be  seen  through  a  good  telescope  when  the  air  is 


VOLCANOES  OF  THE  MOON  213 

quiet.  While  there  are  no  parts  of  the  moon's  surface 
that  have  not  been  carefully  examined  in  detail  probably 
thousands  of  times  by  acute  astronomers,  there  are  still 
comparatively  large  areas  of  the  earth  that  have  never 
been  once  trodden  by  civilized  man. 

When  I  speak  of  all  parts  of  the  moon's  surface,  I  only 
mean  those  parts  that  are  turned  towards  us.  You  may 
possibly  be  ignorant  of  the  fact  that  the  moon  always 
turns  exactly  the  same  face  towards  the  earth.  Not  only 
has  no  man  ever  seen  the  opposite  side  of  the  moon,  but 
he  never  can  hope  to  see  it  while  he  remains  on  the  earth. 
This  is  because  the  moon  turns  or  rotates  on  its  axis  in 
exactly  the  same  time  that  it  revolves  in  its  orbit. 

When  I  say  that  the  time  of  rotation  is  the  same  as  the 
time  of  revolution  of  the  moon,  I  do  not  mean  that  it  is 
almost  the  same,  but  that  it  is  exactly  the  same.  If  it 
differed  even  but  a  small  fraction  of  a  second,  a  time  would 
come  when  we  would  be  able  to  see  the  other  side  of  the 
moon.  Now,  since  astronomers  have  made  careful  pic- 
tures of  the  moon,  many,  many  years  ago,  we  can  see  by 
comparing  them  with  photographs  taken  at  the  present 
time  there  has  been  no  change  whatever  in  that  face  of 
the  moon  which  is  turned  towards  us,  and  this,  of  course, 
proves  beyond  question,  that  the  time  of  the  moon's 
rotation  during  this  great  period  has  remained  exactly 
the  same  as  the  time  of  its  revolution. 

It  may  possibly  seem  to  you  that  it  cannot  be  a  matter 
of  great  importance  in  a  book  like  this  on  the  Wonders 
of  Volcanoes  and  Earthquakes,  whether  or  not  the  moon 
always  turns  its  face  towards  the  earth;  on  the  contrary, 
it  is  a  matter  of  the  greatest  importance  since  by  it  we  can 
prove  positively  that  the  moon  was  at  one  time  at  least 
in  a  partly  fluid  condition.  It  was  the  presence  of  this 
partly  fluid  interior  that  resulted  in  the  time  of  the  moon's 


214          VOLCANOES  AND  EARTHQUAKES 

rotation  agreeing  exactly  with  the  time  of  its  revolution. 
The  tides  of  the  earth  set  up  in  the  moon's  molten  interior, 
tides,  that  instead  of  reaching  twice  every  day  the  height 
of  a  few  feet  only,  were  set  up  in  the  molten  mass  in  the 
moon's  interior,  probably  reaching  miles  in  height,  rapidly 
decreased  the  time  of  the  moon's  rotation  until  the  moon 
rotated  once  only  during  every  complete  revolution. 

Even  now  that  the  moon  is  probably  solid  throughout, 
the  time  of  its  rotation  and  revolution  exactly  agree  be- 
cause, while  in  a  molten  condition,  the  action  of  the  earth 
changed  its  shape  from  that  of  an  exact  sphere  to  a  sphe- 
roid, with  its  longest  axis  in  the  direction  of  the  earth. 
Even,  therefore,  if  the  moon  at  any  time  began  to  rotate 
faster  than  the  earth,  the  earth  acting  on  its  projecting 
surface  retarded  it  until  the  time  of  its  rotation  agreed 
exactly  with  the  time  of  its  revolution. 

It  was  at  one  time  believed  that  the  moon  had  no  at- 
mosphere. It  is  now  known,  however,  that  it  has  an  at- 
mosphere. It  is  true  this  is  a  rare  atmosphere,  probably 
not  greater  in  density  than  the  one-ten  thousandth  of  the 
earth's  atmosphere.  This  important  question  was  settled 
once  for  all  on  August  12th,  1892,  at  the  Harvard  Observa- 
tory at  Arequipa,  Peru,  when  a  photograph  was  taken 
of  an  object  on  the  moon.  It  could  be  readily  seen  on 
examining  this  photograph  that  the  light  coming  from 
the  moon  experienced  a  bending,  known  as  refraction, 
in  passing  from  the  space  outside  the  moon  to  its  atmos- 
sphere  on  to  its  surface. 

Of  course,  when  the  moon  was  thrown  off  from  the  earth 
by  reason  of  its  great  centrifugal  force,  it  carried  along 
with  it  a  portion  of  the  earth's  atmosphere.  But  since 
the  quantity  of  matter  in  the  moon  is  only  about  one- 
eightieth  of  that  of  the  earth,  the  force  of  gravity  on  the 
moon  is  much  smaller  than  that  on  the  earth,  being 


VOLCANOES  OF  THE  MOON  215 

almost  exactly  one-sixth  that  of  the  earth's  gravity.  In 
other  words,  if  you  could  succeed  in  reaching  the  moon's 
surface,  you  would  only  weigh  one-sixth  of  what  you 
weigh  on  the  earth,  but  then  you  could  carry  a  weight  six 
times  heavier  with  no  greater  effort,  and,  as  for  running, 
jumping,  and  other  athletic  exercises,  the  surface  of  the 
moon  would,  indeed,  be  a  great  place  on  which  to  break 
records,  since  one  could  readily  jump  six  times  higher, 
put  the  shot  six  times  further,  than  on  the  earth,  or  go 
through  most  other  athletic  exercises  with  a  correspond- 
ing increase. 

Without  going  any  further  into  this  question  it  will  be 
sufficient  to  say  that  the  moon's  present  atmosphere  is  be- 
lieved to  consist  of  carbonic  acid  gas,  and  that  while  on 
the  general  surface  of  the  moon  this  atmosphere  must  be 
very  rare,  yet,  at  the  bottom  of  the  great  fissures  that  cross 
the  moon's  surface,  it  may  possess  a  fairly  great  density, 
especially  if  the  moon  still  possesses  feeble  volcanic 
activity;  that  carbonic  acid  gas  is  still  being  given  off 
from  the  inside  of  the  moon  as  we  know  it  is  being  given 
off  from  inside  the  earth. 

Under  the  best  conditions  of  atmosphere  and  telescope, 
we  can  see  the  moon's  surface  as  it  would  appear  at  a 
distance  varying  from  800  miles  to  300  miles  from  the 
earth.  With  a  fifteen-inch  telescope,  under  perfect  con- 
ditions of  vision,  objects  can  be  seen  as  if  they  were  at  a 
distance  of  800  miles  from  the  earth,  and  with  the  most 
powerful  glasses,  and  the  best  conditions  of  atmosphere 
this  distance  can  be  reduced  to  about  300  miles.  This 
would  enable  us  to  clearly  see  large  objects  like  rivers, 
lakes,  seas,  or  forests,  if  they  existed,  but  would  not  be 
sufficient  to  enable  us  to  see  houses,  buildings,  or 
roads. 

When  we  come  to  examine  the  surface  of  the  moon 


216          VOLCANOES  AND  EARTHQUAKES 

under  the  most  favorable  conditions,  we  find  that  it  is 
extremely  irregular.  There  are  plenty  of  high  mountains. 
These  mountains  are  not  collected  in  ranges  as  they  are 
on  the  earth's  surface,  but  are  completely  separated  from 
each  other,  and  are  scattered  in  great  numbers  over  the 
moon's  surface. 

You  may  form  some  idea  of  the  number  of  volcanoes 
that  have  been  observed  on  the  moon  when  I  tell  you 
that  as  many  as  32,000  have  been  seen  on  that  side  of 
the  moon  that  is  turned  towards  the  earth. 

Now  it  is  an  interesting  fact  that  almost  all  these  moun- 
tains possess  great  craters  that  are  not  unlike  some  of 
the  volcanic  craters  we  see  on  the  earth.  The  volcanic 
craters  of  the  moon,  however,  are  of  very  much  greater 
size  than  those  on  the  earth,  many  being  from  fifty  to 
sixty  miles  in  diameter,  while  some  of  them  are  more 
than  100  miles  in  diameter.  Smaller  craters,  say  from 
twenty  to  twenty-five  miles  in  diameter,  can  be  counted 
by  the  hundreds. 

Like  most  of  the  moon's  craters,  the  largest  crater 
more  closely  resembles  one  of  the  pit-craters  or  calderas 
on  the  island  of  Hawaii.  This  volcanic  crater  consists 
of  a  huge  circular  ring  with  a  small  irregular  peak  that 
rises  inside  the  ring.  This  peak,  by  the  way,  might  at 
first  appear  to  resemble  the  crater  of  Vesuvius,  which 
after  a  long  period  of  inactivity  of  the  mountain  during 
the  eruption  that  destroyed  Pompeii  and  Herculaneam 
was  thrown  up  inside  of  what  had  been  left  standing  of 
the  old  crater  of  Somma.  But  it  has  no  crater  at  its 
summit,  and,  therefore,  resembles  rather  the  irregular 
pile  or  rock  that  rises  from  the  surface  of  a  lava  lake 
in  the  craters  of  Mt.  Loa  or  Mt.  Kilauea  in  Hawaii. 

Besides  the  numerous  craters  to  be  seen  on  the  moon's 
surface  there  are  many  lines  of  deep,  crooked  valleys, 


VOLCANOES  OF  THE  MOON  217 

known  as  rills,  that  may  at  one  time  have  been  the  beds 
of  rivers.  Besides  the  rills,  there  are  many  straight  clefts 
about  half  a  mile  in  width,  that  extend  down  into  the  sur- 
face of  the  moon  for  unknown  depths.  These  clefts  can 
be  seen  passing  directly  through  mountains  and  valleys. 
They  are  believed  to  be  cracks  or  fissures  in  the  moon's 
surface. 

On  the  moon  is  a  great  crater  called  Tycho.  It  is 
situated  near  the  moon's  south  pole.  The  great  crater  of 
Tycho  is  by  far  the  most  prominent  object  on  the  moon's 
surface.  It  has  a  system  of  rays  that  extend  for  great 
distances  around  its  craters. 

You  will  also  see  if  you  examine  the  moon's  surface 
by  a  powerful  glass  that  there  are  immense  plains  called 
oceans  or  seas.  By  an  appropriate  custom  the  names  of 
the  different  craters  on  the  moon  are  the  same  as  the  names 
of  the  great  astronomers  and  philosophers  that  have  long 
since  passed  from  their  labors,  such  as  Tycho,  Copernicus, 
Kepler,  Plato,  etc. 

Various  explanations  have  been  given  as  to  the  origin 
of  the  craters  on  the  moon's  surface,  but  without  going 
into  a  discussion  it  may  be  said  that  they  are  now  generally 
regarded  as  having  been  formed  in  the  main  just  as  were 
the  craters  of  the  earth's  volcanoes. 

The  tremendous  size  of  the  moon's  craters  is  of  course 
due  to  the  great  decrease  in  the  force  of  gravity.  This 
would  make  the  craters,  approximately,  six  times  as  great 
as  the  craters  on  the  earth.  Professor  Pickering  points 
out  that  while  the  moon's  craters  resemble  more  closely 
those  of  Hawaii  than  those  of  any  other  of  the  earth's 
volcanoes,  yet  there  is  this  difference  in  them:  that 
while  the  earth's  crater  floors  are  generally  considerably 
higher  than  the  level  of  the  sea,  the  moon's  crater  floors 
are  generally  below  the  level  of  the  surrounding  country. 


218         VOLCANOES  AND  EARTHQUAKES 

Still,  taking  them  all  in  all,  the  craters  of  the  moon's 
volcanoes  resemble  those  of  the  island  of  Hawaii,  or 
again  quoting  from  Pickering: — 

"There  seems,  indeed,  to  be  no  feature  found  upon  the 
moon  which  is  not  presented  by  these  Hawaiian  volcanoes, 
there  is  no  feature  of  the  volcanoes  that  does  not  also 
have  its  counterpart  in  the  moon." 


CHAPTER  XXIII 

EARTHQUAKES 

An  earthquake  is  a  shaking  of  the  earth.  It  may  vary 
in  intensity  from  a  shaking  so  feeble  that  it  requires  the 
use  of  a  delicate  instrument  to  detect  it,  to  a  shaking 
violent  enough  to  overthrow  heavy  buildings,  and  even 
to  make  great  rents  or  fissures  in  the  crust. 

An  earthquake  then  is  an  earth-shake.  It  may  be  caused 
by  anything  capable  of  shaking  the  earth;  for  example, 
as  the  falling  of  a  heavy  weight  on  its  surface.  Now,  a 
shaking  so  caused  is  only  felt  in  the  immediate  neighbor- 
hood of  the  place  the  weight  strikes  the  earth.  On  the 
contrary,  in  an  earthquake,  the  shaking  spreads  in  all 
directions  through  the  earth's  crust,  until,  in  the  case  of 
very  violent  earthquakes,  it  reaches  portions  that  may 
be  situated  many  thousands  of  miles  away  from  where 
the  shock  started.  This  spreading  of  the  earthquake 
waves  through  the  solid  earth  is  not  unlike  the  spreading 
of  the  circular  waves  that  are  set  up  in  a  still  water  sur- 
face when  a  stone  is  tossed  in. 

Any  shaking  of  the  earth's  crust  produces  what  may  be 
called  an  earth-shake  or  earthquake.  The  mere  falling 
of  a  raindrop  on  the  earth  produces  a  slight  shaking. 
The  falling  of  a  heavy  stone  produces  a  stronger  shaking, 
and  sets  up  a  series  of  minute  waves,  generally  called 
vibrations,  that  spread  around  the  place  in  all  directions 
from  where  the  stone  struck.  These  movements,  how- 
ever, while  they  spread  in  all  directions,  just  as  they  do 
[219] 


220  VOLCANOES  OF  THE  EARTH 

in  a  surface  of  a  lake,  when  a  stone  is  thrown  into  it,  are 
of  course  much  more  quickly  stopped  by  the  solid  earth 
than  similar  movements  are  by  the  more  readily  movable 
water. 

But,  while  any  shaking  of  the  earth's  crust  constitutes 
an  earthquake,  yet,  strictly  speaking,  an  earthquake  is 
produced  only  by  some  force  that  acts  suddenly  on  the 
earth,  at  a  point  below  its  surface,  and,  therefore,  out  of 
sight.  This,  of  course,  would  rule  out  all  such  shakings 
as  are  caused  by  bodies  striking  the  outer  surface  of  the 
earth. 

Earthquakes  may  occur  in  any  part  of  the  world,  and 
at  any  time  of  the  day  or  year.  They  do  occur,  how- 
ever, most  frequently  in  certain  parts  of  the  world,  at 
certain  seasons  of  the  year  and  at  certain  hours  of  the 
day. 

Earthquakes  are  far  from  being  unusual  occurrences. 
In  some  parts  of  the  world,  such  as  the  island  of  Java, 
they  are  very  common,  and  in  Japan,  under  certain  cir- 
cumstances, scarcely  a  day  passes  without  one  or  more 
shocks  in  some  part  of  that  little  empire. 

Professor  Mallet,  who  has  made  a  very  extensive  study 
of  earthquakes,  published  in  1850  to  1858,  in  the  Philo- 
sophical Transactions,  brief  abstracts  or  descriptions  of 
all  the  more  important  earthquakes  he  could  find  records 
of  during  the  past  3,456  years.  The  number  of  earth- 
quakes thus  recorded  during  this  period  reached  6,830. 
Of  this  great  number  nearly  one-half  occurred  during 
the  last  fifty  years. 

It  should  not  be  inferred  from  the  above  figures  that 
the  number  of  earthquakes  has  really  increased  so  greatly 
in  the  past  half-century.  The  explanation  of  the  apparent 
increase  is  that  greater  care  has  been  taken  recently  in 
recording  earthquakes,  and  that  an  apparatus  called  a 


EARTHQUAKES  221 

seismometer,  or  earthquake-recorder,  has  been  invented 
which  automatically  produces  a  record  of  the  small- 
est shocks;  so  that  a  great  many  have  been  recorded  that 
would  otherwise  have  passed  undetected. 

It  is  the  opinion  of  Le  Conte  that  if  the  records  of  all 
the  earthquakes  of  3,456  years  had  been  thus  made  there 
would  have  been  found  during  the  entire  time  of  Mallet's 
researches  to  have  occurred  no  less  than  200,000,  while 
during  the  last  four  years  of  Mallet's  records,  the  number 
would  have  probably  reached  two  earthquakes  per  week. 

Since  Mallet's  time,  Prof.  Alexis  Perry  published  (1876) 
a  much  larger  list  of  earthquakes.  Perry  finds  that  from 
1843  to  1872  there  have  been  17,249  earthquakes,  or  575 
every  year.  Perry's  list,  however,  is  incomplete,  since 
it  fails  to  record  earthquakes  that  occurred  in  mid-ocean, 
and  in  the  unexplored  and  uncivilized  parts  of  the  world. 
So  it  seems  likely  that  earthquakes  are  so  common 
that  our  earth,  at  some  part  or  other  of  its  surface,  is 
continually  shaking  or  quaking. 

Earthquakes  are  such  tremendous  phenomena  that 
they  were  necessarily  observed  by  the  ancients.  We  find 
more  or  less  complete  accounts  of  them  in  various  writings. 
Lucretius  (Titus  Carus  Lucretius,  a  great  Roman  poet) 
speaks  as  follows,  in  his  De  Rerum  Natura  (On  the 
Nature  of  Things).  We  use  Munro's  translation  here: 

"  Now  mark  and  learn  what  the  law  of  earthquakes  is. 
And  first  of  all  take  for  granted  that  the  earth  below  us 
as  well  as  above  is  filled  in  all  parts  with  windy  caverns, 
and  bears  within  its  bosom  many  lakes  and  many  chasms, 
cliffs  and  craggy  rocks;  and  you  must  suppose  that  many 
rivers  hidden  beneath  the  crust  of  the  earth  roll  on  with 
violent  waves  and  submerged  stones;  for  the  very  nature 
of  the  case  requires  it  to  be  throughout  like  to  itself. 
With  such  things  then  attached  and  placed  below,  the 


222          VOLCANOES  AND  EARTHQUAKES 

earth  quakes  above  from  the  shock  of  great  falling  masses, 
when  underneath,  time  has  undermined  vast  caverns. 
Whole  mountains,  indeed,  fall  in,  and  in  an  instant  from 
the  mighty  shock  tremblings  spread  themselves  far  and 
wide  from  that  centre.  And  with  good  cause,  since  build- 
ings beside  a  road  tremble  throughout,  when  shaken  by 
a  wagon  of  not  such  very  great  weight;  and  they  rock  no 
less,  where  any  sharp  pebble  on  the  road  jolts  up  the  iron 
tires  of  the  wheels  on  both  sides.  Sometimes,  too,  when 
an  enormous  mass  of  soil  through  age  rolls  down  from  the 
land  into  great  and  extensive  pools  of  water,  the  earth 
rocks  and  sways  with  the  undulation  of  the  water  just  as 
a  vessel  at  times  cannot  rest,  until  the  liquid  within  has 
ceased  to  sway  about  in  unsteady  undulations.  .  .  . 

"The  same  great  quaking  likewise  arises  from  this  cause, 
when  on  a  sudden  the  wind  and  some  enormous  force  of 
air  gathering  either  from  without  or  within  the  earth 
have  flung  themselves  into  the  hollow  of  the  earth  and 
there  chafe  at  first  with  much  uproar  among  the  great 
caverns  and  are  carried  on  with  a  whirling  motion,  and 
when  their  force,  afterwards  stirred  and  lashed  into  fury, 
bursts  abroad  and  at  the  same  moment  cleaves  the  deep 
earth  and  opens  up  a  great  yawning  chasm.  This  fell 
out  in  Syrian  Sidon  and  took  place  at  ^Egium  in  the  Pelo- 
ponnese,  two  towns  which  an  outbreak  of  wind  of  this  sort 
and  the  ensuing  earthquake  threw  down.  And  many 
walled  places  besides  fell  down  by  great  commotions  on 
land  and  many  towns  sank  down  engulfed  in  the  sea  to- 
gether with  their  burghers.  And  if  they  do  not  break  out, 
still  the  impetuous  fury  of  the  air  and  the  fierce  violence 
of  the  wind  spread  over  the  numerous  passages  of  the  earth 
like  a  shivering-fit  and  thereby  cause  a  trembling."  Of 
course,  no  one  at  the  present  time  believes  this  ridiculous 
explanation  as  to  the  cause  of  earthquakes. 


EARTHQUAKES  223 

Aristotle,  a  Greek  philosopher,  speaks  thus  concerning 
earthquakes.  We  quote  the  translation  employed  by 
Mallet: 

"Three  theories  on  the  subject  have  been  handed  down 
to  us  by  three  different  persons;  namely,  Anaxagorus  of 
Klazomene,  before  him  Anaximenes  the  Milesian,  and 
later  than  these  Democritus  of  Abdera. 

"Anaxagoras  says  that  the  ether  of  nature  rises  up- 
ward, but  that  when  it  falls  into  hollow  places  in  the 
lower  parts  of  the  earth  it  moves  it  (the  earth);  because 
the  parts  above  are  cemented  or  closed  up  by  rain,  all 
parts  being  by  nature  equally  spongy  or  full  of  cavities, 
both  those  which  are  above  (where  we  live)  and  those 
which  are  below.  Of  this  opinion  it  may  perhaps  be  un- 
necessary to  say  anything,  as  being  foolish,  for  it  is  absurd 
to  suppose  that  things  would  thus  exist  above  and  beneath, 
and  that  the  parts  of  bodies  which  have  weight  would 
not  on  every  side  be  borne  to  the  earth,  and  those  which 
are  light,  and  fiery,  rise;  especially  since  we  see  the  surface 
of  the  earth  to  be  convex  and  spherical,  the  horizon  con- 
stantly changing  as  we  change  our  place,  at  least  as  far 
as  we  know.  And  it  is  also  foolish  to  assert  on  the  one 
hand  that  it  remains  in  the  air  on  account  of  its  great 
size,  and  on  the  other  to  say  that  it  is  shaken,  when 
struck  from  beneath  upwards.  And  besides  these  objec- 
tions, it  is  to  be  remarked  that  he  has  not  treated  of  the 
attendant  circumstances  of  earthquakes,  for  neither  every 
time  nor  place  is  subject  to  these  convulsions. 

"But  Democritus  says,  that  the  earth  being  full  of 
water,  and  receiving  much  also  by  means  of  rain,  is  moved 
by  this.  For  when  the  water  increases  in  bulk,  because 
the  cavities  cannot  contain  it,  in  its  struggles  it  causes  an 
earthquake.  And  when  the  earth  becomes  partially 
dried  up,  the  water  being  drawn  from  the  full  reser- 


224         VOLCANOES  AND  EARTHQUAKES 

voirs  into  those  which  are  empty,  in  passing  from  one 
to  the  other,  by  its  movements  it  causes  an  earthquake 
also. 

"Anaximenes,  however,  says  that  the  earth,  when 
parched  up  and  again  moistened,  cracks,  and  by  the 
masses  thus  broken  off  falling  on  it,  is  shaken;  wherefore 
earthquakes  occur  in  drouths  and  again  in  times  of  rain; 
in  drouths,  because,  as  we  have  said,  it  cracks,  when 
highly  dried,  and  then,  when  moistened  over  again,  it 
cracks  and  falls  to  pieces.  Were  this  the  case,  however, 
the  earth  ought  to  appear  in  many  places  subsiding. 
Why  then  is  it  that  hitherto  many  places  have  been 
very  subject  to  these  convulsions  which  do  not  present 
any  such  remarkable  differences  from  others?  Yet  such 
ought  to  be  the  case.  And,  moreover,  those  who  think 
thus  must  assert  that  earthquakes  constantly  become 
less  and  less,  and  at  last  cease  altogether.  For  the  con- 
tinual condensation  of  the  earth  would  cause  this.  Where- 
fore, if  this  be  not  the  fact,  it  is  plain  that  this  is  not  the 
correct  explanation." 

Besides  the  above,  there  are  numerous  references  to 
earthquakes  in  the  works  of  other  writers.  Thales, 
Seneca,  and  Pliny  all  speak  of  these  phenomena  and 
appear  to  describe  correctly  the  movement  of  the  earth 
in  waves  both  in  the  solid  land,  as  well  as  on  the  sea. 

Coming  down  to  less  ancient  writers,  Mallet  refers  to 
a  book  by  Fromondi,  published  in  Antwerp,  in  1527, 
that  contains  much  valuable  and  interesting  information. 
Among  other  things  Fromondi  declares  that  in  the  year 
369,  in  the  reign  of  Valentinian,  there  was  a  great  earth- 
quake that  shook  nearly  the  entire  world  and  that  an- 
other earthquake  of  almost  equal  severity  occurred  in 
1116.  He  also  states  that  in  1601  an  earthquake  con- 
tinued for  nearly  forty  days;  that  a  great  earthquake  in 


EARTHQUAKES  225 

Italy,  in  1538,  lasted  fifteen  days,  and  that  another,  in 
Spain,  lasted  for  nearly  three  years. 

This  does  not  mean  that  these  earthquakes  actually 
continued  to  shake  the  earth  violently  for  the  times 
mentioned.  These  are  only  the  times  during  which,  at 
intervals  of  greater  or  less  length,  successive  shocks  were 
felt  in  these  localities. 

Another  of  the  less  ancient  writers  referred  to  by  Mallet 
is  Travagini,  who  published  a  book  in  Venice  in  1683. 
This  book  contains  a  description  of  a  terrible  earthquake 
occurring  in  Italy  on  the  6th  of  April,  1667,  which  affected 
large  portions  of  the  country  adjacent  to  Ragusa. 

Without  attempting  at  present  to  discuss  the  various 
theories  of  earthquakes,  it  will  suffice  to  say  that  earth- 
quakes can  be  divided,  according  to  their  origin,  into  two 
classes:  volcanic  earthquakes,  or  earthquakes  that  are 
caused  by  practically  the  same  forces  that  cause  volcanoes, 
and  tectonic  l  earthquakes,  or  those  produced  by  the  slip- 
ping of  a  large  mass  of  rock  lying  along  the  lines  of  old 
or  new  fract\ires. 

Earthquakes  of  the  first  class  are  found  especially  in 
volcanic  districts,  while  those  of  the  second  class  are 
found  in  all  parts  of  the  world,  whether  in  volcanic  dis- 
tricts or  elsewhere.  According  to  Dana,  earthquakes  of 
the  second  class  generally  start  in  the  neighborhood  of 
mountains,  where  old  lines  of  fractures  are  especially 
abundant. 

As  regards  the  direction  of  the  shaking  movements  of 
the  earth,  earthquakes  can  be  divided  into  three  different 
classes:  explosive  earthquakes,  or  those  in  which  the  force 
acts  vertically  upwards;  horizontal  earthquakes,  or  those 
in  which  the  force  moves  in  a  more  or  less  horizontal 

1  Tectonic  Earthquake.  An  earthquake  due  to  the  sudden  slip  of 
faulted  strata. 


226         VOLCANOES  AND  EARTHQUAKES 

direction,  or  parallel  to  the  general  surface  of  the  earth, 
and  rotary  earthquakes,  or  those  in  which  the  earth  rotates 
or  moves  in  great  eddies  or  whirls. 

When  the  earthquake  wave  is  started  below  the  earth's 
surface,  it  spreads  through  the  crust  in  all  directions. 
The  direction  these  waves  will  have  on  emerging,  or  com- 
ing out  of  the  surface,  will  depend  on  the  distance  of  this 
point  from  the  place  the  waves  started.  When  a  place  is 
situated  directly  over  where  the  wave  started,  the  waves 
will  emerge  so  as  to  move  vertically  upwards,  so  that  the 
earth  at  this  point  will  be  shaken  by  an  explosive  earth- 
quake. As  the  point  where  the  waves  pass  out  is  situated 
further  and  further  from  the  place  where  the  waves  start, 
the  waves  will  emerge  more  nearly  horizontally,  the  greater 
the  distance  from  the  source. 

In  explosive  earthquakes,  which,  as  just  explained, 
occur  at  areas  almost  immediately  above  the  point  where 
the  disturbance  starts,  the  force  is,  generally  speaking, 
the  greatest.  In  earthquakes  of  this  character  the  force 
is  sometimes  sufficiently  great  to  throw  large  bodies  high 
up  into  the  air.  In  the  case  of  the  great  Riobamba  earth- 
quake of  1797,  the  force  was  not  only  sufficiently  great  to 
fracture  the  earth  in  various  places,  but  also  to  throw 
bodies  lying  on  the  surface  great  distances  into  the  air. 
Bodies  of  men  were  thrown  several  hundred  feet  into  the 
air  and  were  afterwards  found  on  the  other  side  of  a  broad 
river  or  high  up  on  the  side  of  a  hill. 

It  is  possible  that  Humboldt  did  not  inquire  with  as 
much  care  as  he  should  have  done  into  these  reports. 
They  were  probably  greatly  exaggerated,  since  it  is  diffi- 
cult to  understand  how  a  force  great  as  this  would  have 
failed  to  detach  the  soil  at  these  places,  and  hurl  it  after 
the  people.  This  much,  however,  can  be  accepted,  that 
the  upward  force  was  very  great. 


EARTHQUAKES  227 

In  the  great  Calabria  earthquake  of  March,  1783, 
Dolomieu  states  that  the  tops  of  the  granite  hills  of  Cala- 
bria were  distinctly  seen  to  rise  and  fall.  In  some  cases 
houses  were  suddenly  raised  a  great  distance  in  the  air, 
and  were  afterwards  brought  down  again  to  a  position  of 
rest,  at  a  higher  level  without  any  damage  occurring  to 
them.  In  a  similar  manner  during  the  Caracas  earth- 
quake of  March,  1812,  the  ground  was  seen  to  rise  and 
fall  in  a  nearly  vertical  direction.  But,  perhaps,  one  of 
the  most  terrible  earthquakes  of  this  character  was  the 
earthquake  that  destroyed  the  greater  part  of  Jamaica 
in  June,  1793.  During  this  earthquake  the  entire  surface 
of  the  ground  at  Port  Royal  assumed  the  appearance  of 
a  rolling  sea.  Houses  were  shifted  from  their  old  sites. 
Many  of  the  inhabitants  who  had  succeeded  in  escaping 
from  the  city  to  the  neighboring  country  were  thrown 
great  distances  into  the  air.  Some  of  these,  by  good 
fortune,  fell  into  the  harbor,  from  which,  in  some  cases, 
they  escaped  with  their  lives.  Here  again  the  projectile 
force  was  probably  greatly  exaggerated. 

Vertical  movements  characterized  the  great  earthquake 
of  Lisbon,  on  November  1st,  1755,  the  city  appearing  to 
have  been  not  far  from  the  point  of  origin. 

The  commonest  type  of  earthquakes  is  the  horizontal, 
where  the  waves  emerge  at  the  surface  in  a  direction  either 
horizontal  or  parallel  to  the  general  surface,  or  at  least 
inclined  to  it  at  a  very  small  angle.  Where  the  materials 
of  the  earth's  crust,  through  which  the  waves  spread,  are 
of  the  same  kind  and  of  the  same  density  in  all  directions, 
the  area  shaken  is  approximately  circular,  but  where 
the  materials  of  the  crust  are  more  or  less  dense  in  some 
directions  than  in  others,  the  area  of  disturbance  is  of 
course  oblong  or  elliptical. 

In  some  cases  earthquakes  of  the  horizontal  type  are 


228         VOLCANOES  AND  EARTHQUAKES 

limited  almost  entirely  to  a  single  direction.  This  is 
especially  the  case  with  earthquakes  that  occur  in 
mountainous  districts.  These  earthquakes  are  known  as 
linear  earthquakes,  since  they  spread  almost  in  a  single 
line. 

When  earthquake  waves  pass  from  one  medium  to 
another,  that  is,  from  one  kind  of  rock  to  another,  the 
greater  portion  of  the  waves  is  refracted  or  bent  out  of 
their  straight  direction  as  they  pass  into  the  new  medium; 
a  part  of  the  waves,  however,  are  reflected.  It  is  these 
reflected  waves  that  probably  cause  rotary  earthquakes. 

The  speed  with  which  the  surface  waves  move  outwards 
in  all  directions,  varies  not  only  with  the  force  of  the 
wave,  but  also  with  the  kind  of  material  through  which 
they  pass.  This  velocity  may  be  in  the  neighborhood  of 
twenty  miles  per  second,  while  in  others  the  velocity  is 
as  great  as  140  miles  per  second. 

Naturally,  one  would  suppose  that  the  most  severe 
earthquakes  are  those  in  which  the  waves  move  the  most 
rapidly.  On  the  contrary,  however,  the  comparatively 
feeble  shocks  are  sent  through  the  earth  with  greater 
velocity. 

In  rotary  earthquakes,  as  the  name  indicates,  the  ground 
is  whirled  or  twisted  in  the  manner  of  a  violent  eddy,  and 
is  often  left  in  this  twisted  condition.  In  the  great  Cala- 
bria earthquake,  huge  blocks  of  stone  forming  obelisks 
were  twisted  on  one  another  in  a  manner  represented  in 
Fig.  39.  In  this  case  the  pedestals  remained  unaffected, 
but  the  separate  blocks  of  stone  were  partially  turned 
around,  as  shown.  During  this  earthquake  the  earth 
was  so  twisted  that  trees,  which  had  been  planted  in 
straight  lines  before  the  earthquake,  were  left  standing 
in  zigzags.  During  the  great  Charleston  earthquake, 
South  Carolina,  the  chimney-tops  of  the  houses  were 


EARTHQUAKES  229 

separated  at  places  where  they  joined  the  roof  and 
were  twisted  around  these  places  without  being  over- 
thrown. In  some  of  the  houses  wardrobes  or  bureaus 


FIG.  39.     HEAVY  STONE  OBELISKS  TWISTED  BY 
CALABRIAN  EARTHQUAKE  OF  1783 


were  turned  at  right  angles  to  their  former  positions,  and 
in  some  cases  were  even  found  with  their  faces  turned 
towards  the  wall. 

Mallet  suggests  that  in  some  cases  the  rotary  motion  is 
more  apparent  than  real,  being  due  only  to  a  to-and-fro 
motion  without  any  twisting,  the  apparent  turning  being 
due  to  the  greater  freedom  of  motion  of  the  object  in  one 
direction  than  in  another.  A  twisting  motion,  however, 
has  actually  taken  place  in  some  earthquakes. 

While  separate  shocks,  in  a  given  locality,  may  follow 
one  another  at  intervals  for  fairly  long  times,  yet  the 
principal  shock  or  shake  that  produces  the  greatest 
damage  is  generally  of  exceedingly  short  duration.  In 
the  Caracas  earthquake  the  greatest  destruction  was 
accomplished  in  about  one  minute.  There  were  three 


230         VOLCANOES  AND  EARTHQUAKES 

distinct  shocks,  each  of  which  lasted  but  three  or  four 
seconds.  The  great  Calabria  earthquake,  of  1783,  lasted 
but  two  minutes.  The  earthquake  of  Lisbon,  in  1755, 
lasted  five  minutes,  but  the  first,  and  worst,  shock,  was 
only  from  five  to  six  seconds. 


CHAPTER  XXIV 

SOME  OF  THE  PHENOMENA  OF  EARTHQUAKES 

The  nature  of  an  earthquake  and  the  movements  of  its 
waves  from  their  starting  place  having  now  been  briefly 
described,  it  remains  to  explain  some  of  the  strange 
phenomena  that  precede,  accompany,  or  follow  one. 

Next  to  the  violent  shaking  of  the  earth's  crust,  perhaps 
the  most  wonderful  and  impressive  thing  is  the  great 
variety  of  sounds  and  noises.  These  occur  not  only  while 
the  earth-waves  are  passing  through  the  crust  at  any  place, 
but  also  long  before  the  principal  shocks  reach  the  place, 
as  well  as  long  after  they  have  passed. 

Earthquake  sounds  vary  almost  infinitely,  both  in 
intensity  and  character.  Some  are  like  the  gentle  sigh- 
ings  of  the  wind,  or  resemble  faint  mysterious  whis- 
perings; some  are  not  unlike  the  confused  murmurings 
of  a  crowded  room;  some  resemble  the  sounds  of  a  busy 
street.  Some  sounds  are  full  and  strong,  like  the  deep 
bass  notes  of  a  large  organ.  Others  resemble  the  din  of  a 
great  battle  with  the  reports  of  the  large  guns.  Still 
others  reach  the  intensity  of  continuous  peals  of  thunder. 
But  we  can  better  understand  the  nature  of  earthquake 
sounds  from  an  actual  description  of  them  in  a  number  of 
great  earthquakes,  and  by  inquiring  at  the  same  time  into 
any  of  the  peculiar  facts  connected. 

Humboldt  in  his  great  work,  "Cosmos,"  thus  describes 
the  varied  voice  of  the  earthquake: 

"It  is  either  rolling  or  rustling,  or  clanking,  like  chains 
[231] 


232        VOLCANOES  AND  EARTHQUAKES 

being  moved,  or  like  near  thunder,  or  clear  and  ringing, 
as  if  obsidian  or  some  other  vitrified  masses  were  struck 
in  subterranean  cavities." 

That  the  sounds  produced  during  earthquakes  are  car- 
ried through  the  ground  faster  than  through  the  air  ap- 
pears clear  from  the  fact  that  such  sounds  are  sometimes 
heard  in  deep  mines  when  they  are  not  at  all  heard  on 
the  earth's  surface. 

In  describing  the  earthquake  that  occurred  in  Kamts- 
chatka,  in  1759,  Krashenikoff  of  St.  Petersburg  states 
that  noises  were  heard  like  the  rushing  of  a  strong  under- 
ground wind,  accompanied  by  a  hissing  sound,  which 
resembled  the  sizzlings  heard  when  red  hot  coals  are 
thrown  in  water. 

In  an  earthquake  that  occurred  in  Lincolnshire,  Eng- 
land, February  6th,  1817,  a  noise  was  heard  closely  re- 
sembling the  sounds  of  wagons  running  away  on  a  road. 
So  complete  and  convincing  was  the  resemblance  that 
several  wagoners  on  one  of  the  roads  drew  their  teams  to 
one  side  so  as  to  permit  the  runaway  to  pass  safely. 

Another  kind  of  noise  heard  during  earthquakes  is  a 
loud  hollow  bellowing.  Sometimes,  however,  the  sounds 
are  more  musical  in  their  nature,  being  not  unlike  those 
produced  by  a  very  large  organ  pipe.  At  other  times  they 
resemble  the  noises  produced  when  steam  is  blown  into 
cold  water. 

The  following  account  of  earthquake  sounds  is  given  by 
Daubeny,  in  his  book  on  volcanoes.  It  appears  that 
during  March,  1822,  the  people  living  on  the  island  of 
Melida,  opposite  Ragusa,  in  Dalmatia,  were  greatly 
alarmed  by  sounds  that  at  first  they  believed  due  to 
cannonading  either  at  sea  or  on  the  neighboring  coast. 
They  afterwards  found  that  these  sounds  were  due  to 
something  that  was  taking  place  under  the  ground.  The 


PHENOMENA  OF  EARTHQUAKES   233 

noises  continued  at  intervals  until  August  23d,  1823, 
when  a  great  earthquake  occurred,  during  which  one  of 
the  highest  mountains  on  the  island  was  cleft  or  split  in 
one  place.  The  underground  noises  continued  from  time 
to  time  and  so  frightened  the  people  that  they  were  about 
to  leave  the  island  permanently  and  emigrate  to  the 
mainland  of  Dalmatia.  They  were  dissuaded  from  doing 
so  by  the  government,  and  while  the  noises  continued  at 
intervals  it  so  happened  that  no  damage  came  to  them. 
It  is  said,  however,  that  twenty  years  after  an  active 
volcano  broke  out  on  the  island. 

There  are  various  causes  that  produce  earthquake 
sounds.  A  very  slight  rubbing  or  grinding  together  of 
rock  surfaces  may  produce  fairly  loud  noises,  the  volume 
of  the  sound  being  increased  by  transmission  through 
the  rock  masses  that  lie  in  the  path  of  the  waves.  An 
example  of  such  an  increase  in  the  loudness  of  sounds  is 
seen  in  the  case  of  several  of  the  large  blocks  of  stone 
used  for  some  of  the  piers  of  Kingston  Harbor,  in  Ireland. 
When  these  rocks  are  moved  together  by  blows  of  the 
waves  they  produce  loud  and  appalling  sounds,  as  if  the 
whole  island  were  being  washed  away.  The  same  rocks, 
however,  when  left  high  and  dry  on  the  falling  of  the  tide, 
can  be  caused  to  rub  together,  when  moved  by  the  hand. 
Under  these  circumstances,  they  produce  but  feeble 
sounds  that  can  only  be  heard  in  their  immediate  neigh- 
borhood. 

No  doubt,  some  find  it  difficult  to  understand  how  it  is 
possible  for  comparatively  feeble  sound-waves  to  be 
strengthened  by  their  passage  through  large  masses  of 
solids.  This  is  important  and  should  be  made  clear.  As 
everyone  well  knows,  the  ticking  of  a  watch  can  only  be 
heard  at  a  short  distance  when  the  watch  is  held  in  the 
hand,  because  the  sound-waves  cannot  readily  pass 


234         VOLCANOES  AND  EARTHQUAKES 

through  the  body  of  the  person  holding  the  watch  to  the 
earth,  the  materials  of  the  body  not  being  sufficiently 
elastic.  If,  however,  the  watch  be  placed  on  the  bare 
surface  of  a  large  wooden  table  from  which  the  table- 
cloth has  been  removed,  so  that  the  watch  can  come 
directly  in  contact  with  the  wood,  and  nothing  else  is 
placed  on  the  table  but  the  watch,  the  sound-waves  are 
transmitted  to  the  mass  of  the  table  and  its  entire  surface 
sends  them  out  into  the  air.  The  ticking  of  the  watch 
can  then  be  heard  distinctly  in  almost  any  part  of  a  large 
room. 

Mallet  states  that  in  nearly  all  great  earthquakes 
sounds  are  heard  before  the  principal  shock,  and  in  his 
description  of  the  Calabrian  earthquake  Hamilton  says: 

"All  agreed  that  every  shock  seemed  to  come  with  a 
rumbling  noise  from  the  westward,  beginning  with  the 
horizontal  and  ending  with  the  vorticose  (rotary)  motion." 

According  to  Dolomieu,  during  the  Lisbon  earthquake, 
the  shocks  were  preceded  "by  a  loud  subterranean  noise 
like  thunder,  which  was  renewed  for  every  shock.  .  .  . 
This  great  shock,"  he  says,  referring  to  one  of  the  great 
upward  shocks,  "  occurred  without  the  prelude  of  any 
slight  shocks,  without  any  notice  whatever  as  suddenly 
as  the  blowing  up  of  a  mine.  .  .  .  Some,  however,  pre- 
tend that  a  muffled  interior  noise  was  heard  almost  at 
the  same  moment." 

The  noises  do  not  generally  continue  long  after  the 
earthquake  shocks.  In  some  cases,  however,  a  very  loud 
noise  is  heard  at  intervals  for  a  considerable  length  of 
time  after  the  principal  shock.  This  was  the  case  at  Quito 
and  Ibarra,  in  which  a  great  noise  was  heard  for  from 
eighteen  to  twenty  minutes  after  the  principal  shock.  In 
a  similar  manner  during  the  earthquake  of  October,  1746, 
at  Lima,  and  Callao,  South  America,  peals  of  under- 


PHENOMENA  OF  EARTHQUAKES    235 

ground  thunder  were  heard  at  Truxillo  for  fifteen  min- 
utes after  the  principal  shock.  In  such  cases  it  seems 
probable  that  the  noises  were  not  caused  by  the  same 
impulses  that  caused  the  original  shock,  but  by  the  forces 
that  caused  the  subsequent  shock. 

Humboldt  relates  that  in  1784  there  were  noises  heard 
at  Guanajuato,  from  the  9th  to  the  12th  of  February. 
They  were  not,  however,  followed  by  an  earthquake. 

Humboldt  also  states  that  in  an  earthquake  which 
occurred  on  the  30th  of  April,  1812,  on  the  banks  of  the 
Orinoco  River,  in  South  America,  a  loud  thundering  noise 
was  heard,  without,  however,  any  shock,  but  at  this  time 
a  volcano  on  the  island  of  St.  Vincent,  in  the  Lesser 
Antilles,  although  some  632  miles  to  the  northeast,  was 
pouring  out  streams  of  lava.  Again  in  the  great  eruption 
of  Cotopaxi,  in  1734,  underground  noises  were  heard  as 
if  cannon  were  being  fired.  These  sounds  were  distinctly 
heard  at  as  great  a  distance  as  Honda  on  the  banks  of  the 
Magdalena  River.  Now,  bearing  in  mind  that  the  crater 
of  Cotopaxi  is  situated  on  the  high  plateau  of  Quito,  in  a 
region  full  of  valleys  and  fissures,  it  would  seem  that  for 
the  sounds  to  have  been  sent  through  the  436  miles 
between  the  mountains  and  the  valley  of  the  Magdalena 
River,  the  waves  must,  for  the  greater  part,  have  been 
transmitted  through  the  solid  earth  at  some  considerable 
distance  below  the  surface. 

Mallet  states  that  the  underground  noises  which  con- 
tinued for  more  than  a  month  from  the  midnight  of 
January  9th,  1784,  at  Guanajuato,  were  not  followed  by 
any  earthquake  shocks,  that  it  was  if  as  thunder  clouds 
occupied  the  space  below  the  surface  at  that  part  of  the 
earth  and  from  these  clouds  there  came  the  slow  rolling 
sounds  like  short,  quick,  snaps  of  thunder. 

Major  Button  in  his  book  entitled  "Earthquakes  in 


236         VOLCANOES  AND  EARTHQUAKES 

the  Light  of  the  New  Seismology"  gives  the  following 
as  the  principal  signs  that  herald  the  coming  earthquake 
in  the  open  country. 

"The  first  sensation  is  the  sound.  It  is  wholly  unlike 
anything  we  have  ever  heard  before,  unless  we  have  al- 
ready had  a  similar  experience.  It  is  a  strange  murmur. 
Some  liken  it  to  the  sighing  of  pine-trees  in  the  wind,  or 
to  falling  rain;  others  to  the  distant-  roar  of  the  surf; 
others  to  the  far-off  rumble  of  the  railway  train;  others 
to  distant  thunder.  It  grows  louder.  The  earth  begins 
to  quiver,  then  to  shake  rudely.  Soon  the  ground  begins 
to  heave.  Then  it  is  actually  seen  to  be  traversed  by 
visible  waves  somewhat  likes  waves  at  sea,  but  of  less 
height  and  moving  much  more  swiftly.  The  sound  be- 
comes a  roar.  It  is  difficult  to  stand,  and  at  length  it 
becomes  impossible  to  do  so.  The  victim  flings  himself  to 
the  ground  to  avoid  being  dashed  to  it,  or  he  clings  to  a 
convenient  sapling,  or  fence-post,  to  avoid  being  over- 
thrown. The  trees  are  seen  to  sway  sometimes  through 
large  arcs,  and  are  said,  doubtless  with  exaggeration,  to 
touch  the  ground  with  their  branches,  first  on  one  side, 
then  on  the  other.  As  the  waves  rush  past,  the  ground  on 
the  crests  opens  in  cracks  which  close  again  in  the  troughs. 
As  they  close,  the  squeezed-out  air  blows  forth  sand  and 
gravel,  and  sometimes  sand  and  water  are  spurted  high 
in  air.  The  roar  becomes  appalling.  Through  its  din  are 
heard  loud,  deep,  solemn  booms  that  seem  like  the  voice 
of  the  Eternal  One,  speaking  out  of  the  depths  of  the 
universe.  Suddenly  this  storm  subsides,  the  earth  comes 
speedily  to  rest  and  all  is  over." 

There  are  many  other  curious  phenomena  besides  earth- 
quake sounds  or  noises.  Among  some  of  the  more  inter- 
esting are  the  fire  and  smoke  that  are  seen  to  come  out 
of  fissures  that  have  been  rent  in  the  ground. 


PHENOMENA  OF  EARTHQUAKES    237 

It  is  possible  that  in  many  cases  these  flashes  of  fire  are 
in  reality  produced  by  electric  discharges  that  momen- 
tarily light  the  clouds  of  dust  thrown  up  out  of  the  fis- 
sure. But  sometimes  true  flames  are  seen  escaping  from 
the  fissures.  This  was  the  case  during  the  earthquake  of 
Lisbon,  in  1755,  when  fire  burst  through  fissures  at  several 
places,  burning  with  a  lambent  flame  for  some  hours. 

The  clouds  of  dust  that  follow  the  rending  of  moun- 
tain masses  by  earthquakes  are  probably  to  be  traced 
to  the  fracture  of  the  rock  masses,  the  dust  so  formed 
being  violently  thrown  forth  by  the  air  squeezed  out  of 
the  fissures,  when  they  are  suddenly  closed.  The  violent 
compression  of  this  air  may  raise  this  dust  to  incan- 
descence. 

Mallet  asserts  that  in  many  cases  the  clouds  of  smoke 
observed  do  not  consist  of  true  smoke  like  that  produced 
when  wood  or  vegetable  matters  are  incompletely  burned, 
but  is  only  ordinary  air  mixed  with  sulphurous  acid  gas, 
and  various  other  gases. 

But  not  only  fire  and  smoke  are  seen  at  times  coming 
out  of  fissures  in  the  earth.  A  thing  still  more  frequently 
thrown  out  is  water,  which  often  spouts  forth  along  with 
great  quantities  of  mud,  sand,  and  the  finely  ground 
fragments  of  earthy  materials  generally.  Among  many 
other  instances  where  the  emission  of  water  from  the 
crevices  was  particularly  noticeable,  may  be  mentioned 
the  earthquakes  at  Jamaica  in  1687  and  1692.  Here  the 
water,  in  some  places,  was  thrown  out  of  the  ground  to 
considerable  heights  in  the  air. 

Mallet  calls  attention  to  the  fact  that  the  waters  of 
springs  collect  in  reservoirs  consisting  either  of  fissures 
or  crevices  of  the  rocks,  of  small  width  but  great  depth, 
which  are  vertical  or  inclined  to  the  horizon,  or  in  reser- 
voirs that  are  formed  of  extended  beds  of  sand  or  gravel. 


238          VOLCANOES  AND  EARTHQUAKES 

Now,  when  the  earthquake  waves  moving  horizontally 
over  the  surface  produce  movements  that  squeeze  these 
fissures  together,  the  water  in  the  fissures  is  spurted  out 
in  high  jets,  and  carries  with  it  the  finely  divided  rock  or 
sand  formed  by  the  rubbing  together  of  the  rock  surfaces. 
In  the  case  of  the  reservoirs  consisting  of  beds  of  sand  or 
gravel,  lying  between  impervious  layers,  if,  during  an 
earthquake  motion,  the  land  areas  are  suddenly  lowered, 
the  water  rushing  into  the  cavity  thus  left  will  afterwards 
be  shot  out  with  considerable  force,  when  the  land  is 
suddenly  raised  again. 

Where  there  are  no  direct  openings  in  the  ground  the 
water  will  burst  through  the  crust  in  the  shape  of  great 
vertical  jets,  thus  forming  a  circular  hole,  broken  or  frac- 
tured at  its  edges.  Water  jets  of  this  character  were  es- 
pecially numerous  during  the  earthquake  of  Calabria  in 
1783.  In  a  swampy  plain,  known  as  Rosarno,  many  of 
these  circular  wells  or  openings  about  the  size  of  an  ordi- 
nary carriage  wheel,  though  in  some  cases  much  larger, 
were  to  be  seen  crowded  together.  The  appearance  of 
the  openings  are  represented  in  Fig.  40. 

Some  of  these  were  filled  with  water,  but  the  greater 
number  were  dry  and  filled  with  loose  sand.  These  lat- 
ter, when  examined  by  digging,  were  shown  to  be  funnel- 
shaped,  as  seen  in  Fig.  41.  As  seen,  the  margins  of  the 
wells  exhibit  a  series  of  cracks  or  crevices  extending 
radially  outward  from  the  centre.  Their  origin  is  evi- 
dent. As  the  water  was  violently  expelled  by  the  squeez- 
ing motion  of  the  upper  and  lower  impervious  strata, 
it  shot  upwards,  thus  producing  the  funnel-shaped  tube. 
At  the  same  time  the  force  of  the  eruption  was  suffi- 
ciently great  to  produce  the  radial  fissures  or  fractures 
at  the  sides. 

But  greater  fissures  than  these  have  been  formed  by 


PHENOMENA  OF  EARTHQUAKES    239 


FIG.  40.  CIRCULAR  HOLLOW  FORMED  BY  CALABRIAN  EARTHQUAKE 


earthquakes,  especially  those  of  the  class  created  by  a 
slipping  of  the  earth's  strata.  In  the  case  of  an  earth- 
quake on  the  South  Island  of  New  Zealand,  in  1848,  a 


FIG.  41.   SECTION  OP  CIRCULAR  HOLLOW  FORMED  BY 
CALABRIAN  EARTHQUAKE 

fissure  having  an  average  width  of  eighteen  inches  could 
be  clearly  seen  extending  in  a  direction  parallel  to  the 


240         VOLCANOES  AND  EARTHQUAKES 

mountain  chain  for  a  distance  of  sixty  miles,  and  during 
a  later  earthquake  in  the  same  region,  in  1855,  a  fracture 
was  formed  that  could  be  clearly  traced  for  a  distance  of 
nearly  ninety  miles. 

In  some  cases  these  fissures  or  fractured  parts  of  the 
crust  are  left  with  one  of  their  sides  at  a  higher  level  than 
the  opposite  side.  This  was  the  case  of  the  great  Japanese 
earthquake  of  October  28th,  1891. 

There  are  three  kinds  of  waves  produced  by  earth- 
quakes; namely,  the  earthquake  waves  proper  through 
the  earth;  the  sound  waves  in  the  air,  and  great  forced 
waves  in  the  sea. 

The  sound  waves  of  course  reach  the  air  from  the  point 
of  origin  below  the  earth's  surface  through  the  solid  mate- 
rials of  the  crust,  and  take  on  the  curious  varieties  already 
described  in  connection  with  the  sounds  accompanying 
earthquakes. 

We  have  already  briefly  described  the  manner  in  which 
the  earthquake  waves  travel  through  the  materials  of 
the  earth's  crust.  There  remain  to  be  discussed  the  great 
waves  that  are  rolled  up  in  the  ocean  during  an  earth- 
quake shock.  These  waves  are,  perhaps,  among  the  most 
destructive  phenomena  of  great  earthquakes.  The  fol- 
lowing are  only  some  of  the  more  remarkable  of  such 
waves,  and  have  been  taken  from  Mallet's  collection  of 
earthquake  data. 

During  some  of  the  great  earthquakes  on  the  coasts  of 
Chile  and  Peru,  huge  waves  from  the  ocean  did  great 
damage  when  they  reached  the  land.  In  the  earthquake 
of  1590,  ocean  waves  rushed  for  several  leagues  inland 
over  the  coast  of  Chile,  carrying  with  them  ships  that 
were  left  high  and  dry  as  the  wave  receded.  In  the 
earthquake  of  1687,  Callao  was  inundated  by  a  great 
wave  from  the  Pacific  Ocean,  and  ships  were  carried  a 


PHENOMENA  OF  EARTHQUAKES    241 

full  league  into  the  country.  During  the  earthquake  of 
1746,  Callao  was  again  swept  away  by  a  huge  ocean  wave. 
At  later  times  earthquake  waves  have  caused  great  dam- 
age to  several  other  parts  of  the  coast  of  South  America. 

Ocean  waves  of  this  character  are  formed  by  successive 
upward  and  downward  movements  at  the  bottom  of  the 
ocean,  following  each  other  at  very  brief  intervals.  Le 
Conte  points  out  that  the  sudden  upheaval  of  the  bed  of 
the  ocean  forms  a  huge  mound  in  the  surface  of  the  water 
which  results  in  a  large  wave  that  spreads  rapidly  in  all 
directions.  Waves  produced  in  this  manner  sometimes 
reach  a  height  of  fifty  to  sixty  feet.  They  are  not  readily 
observed  in  the  deep  ocean,  but  as  soon  as  they  reach 
the  shallow  waters  near  the  shore  they  rush  forward,  form- 
ing waves  from  fifty  to  sixty  feet  in  height  and,  rushing 
over  the  land,  sweep  everything  before  them. 

During  the  great  Lisbon  earthquake  of  1755  a  huge 
wave  started  at  a  point  fifty  miles  off  the  coast  of  Portugal. 
Half  an  hour  after  the  earthquake  was  over  several  waves, 
the  largest  of  which  was  sixty  feet  in  height,  rushed  over 
a  part  of  the  city  and  greatly  increased  the  ruin  already 
wrought  by  the  earthquake.  According  to  Le  Conte  the 
great  waves  so  formed  moved  in  all  directions  across  the 
Atlantic  Ocean.  They  were  thirty  feet  high  when  they 
reached  Cadiz,  eighteen  feet  in  height  at  Madeira,  and 
five  feet  on  the  coast  of  Ireland.  They  even  crossed  the 
Atlantic,  being  observed  on  the  coasts  of  the  West  Indies. 

A  great  ocean  wave  accompanied  the  Japanese  earth- 
quake in  1854.  As  in  the  case  of  the  Lisbon  earthquake 
this  wave  started  in  the  bed  of  the  ocean  off  the  coast  of 
Japan  and  only  reached  the  island  half  an  hour  afterwards. 
It  was  thirty  feet  in  height,  and  completely  swept  away 
the  town  of  Simoda. 

Owing  to  water's  greater  freedom  of  motion  earth- 
p 


242         VOLCANOES  AND  EARTHQUAKES 

quake  waves  travel  greater  distances  through  the  water 
than  they  do  on  land. 

Of  course,  great  earthquake  shocks  as  a  rule  cause  a 
very  large  loss  of  life.  The  following  figures  from  Mallet 
give  some  idea  of  the  extent  of  this  loss,  which  is  generally 
a  matter  of  a  few  moments. 

In  the  Lisbon  earthquake,  where  the  worst  shock  lasted 
a  few  seconds,  60,000  people  were  killed.  During  other 
earthquakes  the  losses  have  been  as  follows:  10,000  at 
Morocco;  40,000  in  Calabria;  50,000  in  Syria,  and  prob- 
ably 120,000  in  earthquakes  that  occurred  in  Syria  in 
A.  D.  19  and  in  A.  D.  526. 

But  even  these  figures  give  only  a  meagre  idea  of  the 
vast  loss  of  life  that  has  occurred  during  the  past.  It  is 
said  that  during  the  reign  of  Justinian,  earthquakes  re- 
peatedly shook  the  whole  Roman  world.  The  city  of 
Constantinople  was  visited  by  earthquake  shocks  that 
continued  at  intervals  for  forty  days.  Deep  chasms  were 
opened  in  the  earth  and  huge  masses  were  thrown  into 
the  air.  Enormous  sea-waves  were  formed.  At  Antioch, 
during  the  earthquake  of  May  20th,  A.  D.  526,  250,000 
people  are  believed  to  have  been  killed. 

On  the  31st  of  July,  A.  D.  365,  in  the  second  year  of 
Valentinian,  a  dreadful  earthquake  shook  the  Roman 
world,  and  a  great  wave  rolled  in  from  the  Mediterranean 
and  swept  two  miles  inland,  carrying  ships  over  the  tops 
of  houses.  During  this  earthquake  50,000  people  lost 
their  lives  at  Alexandria. 

In  the  earthquake  of  Messina  in  1692,  74,000  people  are 
said  to  have  been  killed;  and,  according  to  other  accounts, 
100,000.  In  the  year  A.  D.  602,  another  earthquake  at 
Antioch  killed  60,000  people. 

During  the  earthquake  of  Quito,  in  1797,  Humboldt 
estimates  that  40,000  natives  were  either  buried  in  crev- 


PHENOMENA  OF  EARTHQUAKES    243 

ices  in  the  earth,  under  the  ruins  of  buildings,  or  were 
drowned  in  lakes  and  ponds  that  were  temporarily  formed. 

In  this  connection  Mallet  writes  as  follows: 

"Such  are  the  numbers  to  be  met  with  in  narratives, 
and  if  we  suppose  that  there  occurs  one  great  earthquake 
in  three  years  over  the  whole  earth  and  that  this  involves 
the  entombment  of  only  10,000  human  beings,  and  that 
such  has  been  the  economy  of  our  system  for  the  last 
4,000  years,  we  shall  have  a  number  representing  above 
13,000,000  men  thus  suddenly  swallowed  up,  with  count- 
less bodies  of  animals  of  every  lower  class.  Sir  Charles 
Lyell  then  with  good  reason  suggests  that  even  in  our  own 
time  we  may  yet  find  the  remains  of  men  and  of  their 
habitations  and  implements  thus  buried  deep  and  em- 
balmed, as  it  were,  by  earthquakes  that  occurred  in  the 
days  of  Moses  and  the  Ptolemies." 

Necessarily  the  progress  of  a  great  earthquake  wave 
will  produce  great  changes  in  the  earth's  surface  features; 
for  example,  landslides,  where  immense  layers  of  clay  or 
other  material  slip  or  slide  to  a  lower  level  and  are  thrown 
across  the  course  of  a  river,  causing  its  waters  to  be 
dammed  up  and  then  by  spreading  to  form  great  lakes. 

Sometimes,  after  vast  bodies  of  water  have  been  col- 
lected in  this  manner,  disastrous  floods  result  later  from 
a  sudden  giving  way  of  the  barrier,  and  the  loss  thus 
caused  is  occasionally  far  greater  than  that  directly  due 
to  the  earthquake. 

Permanent  changes  of  level  are  frequently  caused  by 
earthquakes,  as,  for  example,  the  coast  of  Chile  during 
the  earthquake  of  November  19th,  1822,  where  the  coast 
for  many  miles  was  raised  from  three  to  four  feet  above 
its  former  plane. 

In  other  cases  the  level  of  the  ground  is  permanently 
lowered.  This  occurred  in  the  Bengal  earthquake  in 


244         VOLCANOES  AND  EARTHQUAKES 

1762,  when  an  area  of  some  sixty  square  miles  suddenly 
sank,  leaving  only  the  tops  of  the  higher  points  above 
water. 

In  some  cases  of  changes  in  the  level  of  the  ground, 
large  areas  being  raised  in  one  place  and  lowered  in  an- 
other, rivers  take  new  courses,  and  their  old  courses  are 
completely  obliterated. 


CHAPTER  XXV 

THE  EARTHQUAKE  OF  CALABRIA  IN  1783 

All  students  of  elementary  geography  are  quick  to 
notice  that  the  extreme  southeastern  part  of  Italy  is 
shaped  something  like  a  boot,  which  appears  to  be  kick- 
ing at  the  island  of  Sicily.  This  part  of  the  Mediterranean 
Sea  has  for  very  many  years  been  the  arena  or  storm 
centre  of  more  or  less  intense  volcanic  activity.  To  the 
northwest  is  the  active  volcano  of  Vesuvius,  as  well  as 
the  volcanic  regions  of  the  Phlegraean  Fields.  Imme- 
diately opposite  the  point  of  Italy,  near  the  toe  of  the 
foot,  is  the  active  volcanic  mountain,  Etna,  while  not  far 
from  this  point  is  the  volcano  of  Stromboli. 

In  1783  this  part  of  the  world  was  visited  by  a  very 
severe  earthquake.  Since  at  that  time  the  country  was 
divided  into  two  parts,  known  as  Upper  Calabria  and 
Lower  Calabria,  this  earthquake  is  sometimes  spoken  of 
as  the  earthquake  of  the  Calabrias,  or  more  simply  as  the 
Calabrian  earthquake. 

The  great  mountain  range  of  the  Apennines,  mainly  of 
granite  formation,  extends  through  the  central  part  of 
Italy.  The  lands  adjoining  the  mountains  on  each  side 
are  flat  and  marshy,  and  consequently  unhealthy. 

Numerous  observers  have  compiled  excellent  accounts 
of  the  Calabrian  earthquake.  These,  having  been  made 
by  educated  persons,  are,  to  a  large  extent  free  from  the 
inconsistencies  and  exaggerations  apt  to  characterize 
descriptions  by  ignorant  persons,  especially  when  in  a 
[245} 


246         VOLCANOES  AND  EARTHQUAKES 

condition  of  excitement  or  alarm.  Among  reliable  writers 
was  Sir  William  Hamilton,  who  made  a  personal  examina- 
tion of  the  region,  soon  after  the  first  severe  shock,  and 
collected  much  valuable  information  for  a  paper  which 
was  afterwards  published  in  the  Philosophical  Trans- 
actions of  the  Royal  Society.  Then,  too,  Dolomieu, 
another  scientific  man  of  high  ability,  made  a  careful 
study  of  the  effects  produced  by  the  earthquake. 

As  can  be  seen  by  an  examination  of  the  map  presented 
in  Fig.  42,  the  part  of  Italy  included  in  the  Calabrias 


FIG.  42.    MAP  OF  THE  CALABRIAN  EARTHQUAKE  OF  1783 


covers  an  area  from  north  to  south  almost  equal  to  two 
degrees  of  latitude.    Although  the  shock  extended  beyond 


EARTHQUAKE  OF  CALABRIA  247 

the  limits  of  Calabria,  since  it  reached  as  far  north  as 
Naples,  as  well  as  over  a  great  part  of  the  Island  of  Sicily, 
the  territory  in  which  the  greatest  damage  was  done  did 
not  exceed  in  area  about  500  square  miles. 

The  southern  part  of  Italy  is  subject  to  frequent  earth- 
quake shocks.  Pignatari,  an  Italian  physician,  asserts 
that  this  region  was  visited  during  1783  by  no  less  than 
949  earthquakes,  of  which  501  were  of  the  first  class,  or 
degree  of  intensity,  while  in  1784,  there  were  151  earth- 
quakes, of  which  ninety-eight  were  of  the  first  class. 

It  seems  that  the  city  of  Oppido,  marked  on  the  above 
map  as  midway  between  the  two  coasts,  was  the  point 
from  which  the  severe  earthquake  of  1783  started.  If 
one  draws  a  circle,  with  a  radius  of  twenty-two  miles, 
around  Oppido  as  a  centre,  the  portions  of  the  Calabrias 
that  were  the  most  affected  will  all  lie  within  this  circle. 

The  great  Calabrian  earthquake  was  attended  by 
numerous  shocks.  The  first  and  the  most  severe  shock, 
that  of  February  5th,  1783,  was  only  two  minutes  in  de- 
stroying most  of  the  houses  in  all  cities,  towns,  and  vil- 
lages on  the  western  side  of  the  Apennines  in  this  part 
of  Italy. 

Another  severe  shock  occurred  on  the  28th  of  March. 
This  shock  was  almost  as  severe  as  that  of  February  5th. 

In  order  to  understand  many  of  the  effects  produced  by 
this  earthquake,  inquiry  must  be  made  into  the  geological 
character  of  the  region.  According  to  Dolomieu,  the  flat 
country  at  the  slopes  of  the  Apennines,  known  as  the 
Plain  of  Calabria,  is  covered  with  sand  and  clay  mixed 
with  sea  shells.  These  strata  have  been  deposited 
by  the  sea  from  materials  that  have  been  obtained  by 
the  decomposition  of  the  granite  mountain  ranges  in  the 
Apennines.  The  plain  is  quite  level  except  where  it  is 
crossed  by  deep  valleys  or  ravines,  which  have  been 


248          VOLCANOES  AND  EARTHQUAKES 

eroded  or  cut  by  the  swift  mountain  torrents.  In  many 
cases,  these  ravines  or  valleys  have  depths  as  great  as 
600  feet.  Their  sides  are  generally  almost  perpendicular. 
Consequently,  as  Lyell  remarks,  throughout  the  length 
of  the  mountain  chain,  the  soil,  which  adheres  but  loosely 
to  the  granite  base  of  the  mountain  chain,  could  therefore 
be  easily  separated  from  the  mountain,  and  sliding  over 
the  solid  steeps  of  the  mountain  could  readily  move, 
especially  through  the  ravines  or  gorges,  to  distances 
in  some  cases  as  great  as  from  nine  to  ten  miles. 

This  peculiarity  of  the  country  must  be  thoroughly 
understood,  since,  otherwise,  it  would  seem  impossible 
that  lands  could  be  carried  several  miles  from  their  former 
position,  and  often  bear  along  with  them  almost  undis- 
turbed houses,  olive  groves,  vineyards,  and  cultivated 
fields. 

The  heaving  of  the  surface  of  the  earth  like  the  waters 
of  the  sea,  so  common  in  severe  earthquakes,  occurred 
during  the  Calabrian  earthquake.  In  some  places  this 
heaving  so  shook  the  trees  that  they  bent  until  their  tops 
touched  the  ground  near  their  base. 

Parts  of  the  ground  were  violently  thrown  upwards 
into  the  air  as  in  the  explosive  type  of  earthquakes.  In 
many  instances  the  large  paving  stones  were  thrown  into 
the  air  and  afterwards  found  with  their  lower  portions 
upwards. 

During  the  earthquake  deep  fissures  were  made  in  the 
earth  at  various  localities  and  there  were,  moreover, 
marked  changes  of  level.  At  Messina  in  Sicily  the  shore 
was  fissured  and  rent  and  while  before  the  convulsion 
the  surface  had  been  level,  it  was  afterwards  found  to  be 
inclined  toward  the  sea. 

According  to  Dolomieu  the  following  curious  incident 
occurred  during  the  passage  of  the  earthquake  waves. 


EARTHQUAKE  OF  CALABRIA 


249 


A  well  in  the  ground  of  one  of  the  convents  of  the  Augus- 
tines,  lined  on  the  inside  with  stones,  was  so  affected  by 
the  upward  thrust  given  to  the  land  that  its  stone  lining 
was  left  projecting  above  the  level  of  the  earth  in  the  form 
of  a  small  tower  some  eight  or  nine  feet  in  height. 

Frequent  instances  occurred  of  deep  fissures  in  the 
surface  of  the  earth.  Many  of  these  remained  open  after 
the  earthquake,  although  in  other  cases  they  were  firmly 
closed  together  before  the  earthquake  shocks  ceased. 

Fig.  43  represents  the  appearance  of  certain  fissures 


FIG.  43.     FISSURES  CAUSED  BY  THE  CALABRIAN  EARTHQUAKE 

in  a  part  of  Calabria  during  this  earthquake.  These 
cracks,  it  will  be  noticed,  radiate  or  pass  outward  in  all 
directions  from  a  central  point,  just  like  the  cracks  that 
are  formed  in  a  glass  window  pane  when  it  is  fractured  by 
a  stone  thrown  against  it. 

Of  course,  the  most  violent  effects  were  near  the  origin 
of  the  earthquake  at  Oppido.  Here  the  formation  of  deep 
fissures  was  common.  In  another  part  of  the  country 
a  number  of  buildings  were  suddenly  swallowed  up  in  a 


250         VOLCANOES  AND  EARTHQUAKES 

central  chasm,  which  almost  immediately  closed,  thus 
permanently  burying  all  these  objects. 

Some  idea  of  the  force  with  which  the  fissures  were  after- 
wards closed  can  be  formed  by  reflecting  on  a  case  where, 
in  order  to  recover  some  of  the  buried  articles,  the  ground 
was  dug  up  at  these  points,  and  it  was  found  that  the 
materials,  human  bodies  and  other  objects,  were  so 
jammed  together  as  to  make  one  compact  mass. 

To  Sir  William  Hamilton  a  place  was  shown  where 
the  fissures,  though,  when  he  saw  them,  they  were  not 
more  than  a  foot  in  width,  had  opened  sufficiently  wide 
during  the  shock  to  swallow  up  a  hundred  goats  as  well 
as  an  ox. 

An  earthquake  that  caused  such  marked  changes  in  the 
appearance  of  the  earth's  surface,  naturally  made  great 
changes  in  the  direction  of  the  rivers.  In  one  case  the 
end  of  a  small  valley  was  so  completely  filled  with  stones 
and  dirt  that  the  water  was  dammed  up,  producing  a 
lake  two  miles  in  length  and  one  mile  in  breadth.  In  a 
similar  manner  no  less  than  215  lakes  were  formed  in 
different  portions  of  Calabria. 

Of  course,  in  the  flat  country  at  the  base  of  the  Apen- 
nines, frequent  landslides  occurred,  the  land  sliding  into 
great  chasms  and  continuing  to  move  down  them  for 
considerable  distances,  so  that  in  many  places  pieces  of 
land  containing  olive  trees,  vineyards,  and  green  fields, 
were  bodily  transported  for  distances  of  several  miles. 
This,  moreover,  was  done  so  quietly  as  to  leave  the  houses 
entirely  uninjured,  and  the  trees  and  other  vegetation 
continuing  to  grow  up  with  apparently  no  marked  de- 
crease in  vitality. 

As  is  usual  in  such  cases,  the  sudden  and  strong  blows 
acting  on  the  waters  of  the  sea,  killed  great  numbers  of 
fish  just  as  does  the  explosion  of  dynamite  at  a  point 


EARTHQUAKE  OF  CALABRIA  251 

below  the  surface  of  the  water;  and  in  a  similar  way  the 
fish  that  usually  live  at  the  bottom  of  the  sea  in  the  soft 
mud,  being  disturbed  by  the  earthquake  shocks,  came 
near  the  surface  where  they  were  caught  in  vast  numbers. 

It  is  an  interesting  fact  that  during  this  earthquake 
the  volcano  of  Stromboli  showed  a  marked  decrease  in 
the  volume  of  smoke  it  gave  out.  Etna,  however,  was 
observed  to  emit  large  quantities  of  vapor  during  the 
convulsion. 

Lyell  tells  the  following  story  of  the  Prince  of  Scilla, 
who  with  many  of  his  vassals  sought  safety  in  their  fish- 
ing boats.  Suddenly,  on  the  night  of  February  5th, 
while  some  of  the  people  were  sleeping  in  the  boat,  and 
others  were  resting  on  a  low  plain  near  the  sea,  in  the 
neighborhood,  another  shock  occurred,  a  great  mass  was 
torn  from  a  neighboring  mountain  and  hurled  with  a 
crash  on  the  plain,  and  immediately  afterwards  a  wave, 
twenty  feet  or  more  in  height,  rolled  over  the  level  plain, 
sweeping  away  the  people.  It  then  retreated,  but  soon 
rushed  back  again,  bringing  with  it  many  of  the  bodies 
of  the  people  who  had  perished.  At  the  same  time  all 
the  boats  were  either  sunk  or  dashed  against  the  beach, 
and  the  Prince  with  1,430  of  his  people  was  destroyed. 

The  total  number  of  deaths  caused  by  this  earthquake 
in  the  Calabrias  and  Sicily  were  estimated  by  Hamilton 
at  40,000.  Besides  these  about  20,000  more  perished  in 
epidemics  that  followed  the  earthquake,  or  died  for  lack 
of  proper  food. 


CHAPTER  XXVI 

THE    GREAT    LISBON    EARTHQUAKE    OF    1755 

Lisbon,  the  capital  of  Portugal,  on  the  Tagus  River,  is 
built  along  both  banks  for  five  miles,  and  on  several  small 
neighboring  hills.  It  is  supplied  with  water  by  means  of 
an  aqueduct,  called  the  Alcantara,  which  brings  the  water 
from  springs  about  nine  miles  to  the  northwest.  For 
portions  of  its  length  the  aqueduct  is  placed  underground, 
but  where  it  crosses  the  deep  valley  of  the  Alcantara  it 
is  supported,  for  a  distance  of  2,400  feet,  by  a  number  of 
marble  arches,  which  in  one  place  are  260  feet  in  height. 
This  fact  is  put  forward  not  merely  for  the  sake  of  its 
artistic  interest,  but  because,  strange  to  relate,  this  part 
of  the  aqueduct  remained  uninjured  during  that  great 
earthquake,  the  greatest  of  modern  times. 

On  the  1st  of  November,  1755,  this  frightful  catastrophe, 
according  to  Lyell,  from  whose  excellent  account  much 
of  the  information  contained  in  this  chapter  has  been 
obtained,  struck  the  beautiful  city  almost  without  any 
warning.  Terrible  sounds  came  suddenly  from  under- 
ground; almost  instantly  afterward  a  violent  shock  threw 
down  the  greater  portion  of  the  city;  in  less  than  six 
minutes  60,000  people  were  killed. 

The  place  from  which  this  earthquake  started  must  have 
been  situated  on  the  bed  of  the  ocean  at  some  distance 
from  the  coast;  for  the  great  wave  thus  raised  in  the 
Atlantic  Ocean  did  not  reach  the  mouth  of  the  Tagus 
River  until  about  half  an  hour  after  the  most  severe 
[252] 


GREAT     LISBON  EARTHQUAKE  253 

shocks  were  over.  The  arrival  of  this  wave  at  the  mouth 
of  the  Tagus  was  announced  by  the  sea  retiring  to  such  an 
extent  as  to  leave  the  bar  dry.  Then  a  huge  wave,  sixty 
feet  in  height,  rolled  in  from  the  ocean  and  completed 
the  work  of  destruction  that  had  been  commenced  by 
the  earthquake. 

So  great  was  the  shock  that  the  mountains  in  the 
neighborhood  were  violently  shaken  and  some  of  them 
split  or  fractured  in  a  most  wonderful  manner. 

Particularly  large  was  the  loss  of  life  in  the  churches 
whither  hundreds  hastened  for  refuge  when  the  shakings 
of  the  earth  began,  for  most  of  these  buildings  fell  and 
buried  the  worshippers.  Another  immense  loss  of  life 
was  caused  by  the  destruction  of  a  large  marble  quay  or 
wharf  that  was  suddenly  swallowed  up  by  the  sea.  While 
the  buildings  in  the  city  were  being  overthrown  by  the 
violent  shakings  of  the  earth,  a  multitude  sought  the 
quay  as  a  flat  place  where  they  could  not  be  injured  by 
the  falling  buildings.  Suddenly,  however,  this  structure 
sank  into  the  water  and  not  only  were  all  the  people 
drowned,  but  none  of  the  bodies  was  ever  afterwards 
found. 

Failure  to  find  any  remnants  of  the  pier  or  any  of  the 
people  who  perished  on  it  has  been  attributed  to  the  for- 
mation of  eddies  or  whirls  that  were  sufficiently  strong 
to  carry  down  vessels  by  suction  similar  to  that  of  the 
famous  maelstrom  off  the  coast  of  Norway.  Of  course, 
in  a  time  of  boundless  excitement  like  that  of  the  Lisbon 
earthquake,  accounts  are  apt  to  be  highly  exaggerated. 
For  example,  assertions  are  made  in  many  books  that 
the  water  left  in  the  harbor  after  the  sinking  of  the  quay 
was  unfathomable.  Now,  in  point  of  fact,  the  depth  of 
this  place  has  been  measured  and  found  to  be  less  than 
100  fathoms. 


254         VOLCANOES  AND  EARTHQUAKES 

When  it  is  remembered  that  not  one  of  the  bodies  of 
the  people  on  that  quay  was  ever  again  seen,  it  is  possible, 
as  Lyell  suggests,  that  a  deep  fissure  or  chasm  opened 
immediately  on  the  ground  on  which  the  quay  stood,  so 
that  it,  together  with  all  on  it,  were  dropped  into  the 
chasm,  which,  closing,  buried  them  deep  in  the  earth. 

The  Lisbon  earthquake  was  especially  noted  for  the 
extent  of  country  affected  by  it.  Humboldt  estimated 
this  area  as  being  more  than  four  times  the  size  of  Europe. 
In  parts  of  this  area  immense  mountain  ranges,  such  as 
the  Pyrenees,  Alps,  etc.,  were  violently  shaken.  When 
the  size  of  these  mountains  is  considered  one  realizes  that 
it  must  have  required  a  mighty  force  to  shake  them. 
These  shakings  were  so  severe  that  they  produced  a  deep 
fissure  in  the  ground  in  France.  Continuing  towards  the 
north  the  solid  earth  was  shaken  as  far  as  the  shores  of 
the  Baltic  and  Norway  and  Sweden,  generally.  This,  of 
course,  included  the  flat  country  of  Northern  Germany. 
The  hot  springs  of  Toplitz  disappeared  for  a  time,  but, 
breaking  out  afterwards,  discharged  such  quantities  of 
muddy  water  that  the  surrounding  country  was  inun- 
dated. 

The  waves  crossed  the  Atlantic,  causing  high  tides  on 
the  island  of  Antigua,  Barbadoes,  and  Martinique,  of  the 
Lesser  Antilles,  where,  instead  of  the  usual  tides  of  two 
feet,  tides  of  twenty  feet  high  were  observed.  Further 
to  the  north  the  waves  reached  the  eastern  shores  of  North 
America,  and  shook  the  continent  as  far  west  as  the  Great 
Lakes,  and  spread  in  the  North  Atlantic  as  far  as  Ice- 
land. 

Toward  the  south  the  waves  affected  parts  of  north- 
western Africa,  where  much  loss  of  life  occurred  in  the 
villages  some  eight  leagues  distant  from  the  city  of 
Morocco.  Here  from  8,000  to  10,000  people  were  killed, 


GREAT  LISBON  EARTHQUAKE  255 

being  swallowed  up  by  deep  fissures  in  the  earth,  which 
afterwards  closed  on  their  bodies. 

Severe  shocks  were  in  many  cases  felt  on  vessels  at  sea. 
In  one  instance,  although  the  vessels  were  at  considerable 
distances  from  where  the  waves  started,  the  captains 
reported  that  the  shocks  were  so  great  that  on  several 
occasions  it  was  believed  the  vessel  had  struck  a  rock,  till, 
on  heaving  the  lead,  they  found  that  they  were  in  very 
deep  water.  In  another  instance,  such  was  the  shock  to 
the  vessel  that  the  planks  on  the  deck  had  their  seams 
opened.  In  still  another  case  several  of  the  sailors  were 
thrown  into  the  air  for  a  distance  of  about  one  and  a  half 
feet. 

It  has  been  frequently  observed  that  when  great 
earthquakes  happen,  curious  changes  take  place  in  the 
level  of  the  waters  of  lakes  entirely  disconnected  with 
the  ocean;  for  example,  mountain  lakes,  far  above  the 
level  of  the  sea,  the  water  suddenly  rising  and  then  re- 
suming its  original  level.  Sometimes  the  waters  of  such 
lakes  have  suddenly  disappeared,  probably  being  drained 
off  through  a  fissure  formed  in  the  bed  of  the  lake.  In 
such  event  the  lake  generally  remains  dry  after  the  pas- 
sage of  the  earthquake. 

At  the  time  of  the  Lisbon  earthquake  it  was  observed 
that  the  water  of  Loch  Lomond  in  Scotland  first  rose 
above  its  ordinary,  then  sank  again  to  its  usual  level. 
This  difference  of  level  is  explained  by  Lyell  as  follows: 
when  the  earthquake  waves  reached  the  lake,  the  water 
being  unable  to  take  the  sudden  shove  given  to  it  by  the 
earthquake  waves,  dashed  over  that  side  of  the  basin 
which  first  received  the  shock.  Assuming  this  to  be  the 
case,  since  the  rise  of  the  level  in  the  water  of  Loch  Lo- 
mond was  two  feet  and  four  inches,  it  is  comparatively 
easy  to  calculate  the  speed  of  movement  that  the  earth- 


256         VOLCANOES  AND  EARTHQUAKES 

quake  waves  had,  when  they  reached  this  body  of  water. 
Calculated  in  this  way  it  would  seem  that  the  waves  had 
a  speed  of  about  twenty  miles  a  minute. 

But  what  especially  characterized  the  Lisbon  earth- 
quake were  the  great  waves  that  were  produced  in  the 
ocean.  Besides  the  huge  wave  that  entered  the  Tagus, 
a  wave  of  the  same  height  swept  eastward  along  the  south- 
ern coast  of  Spain,  and  the  northwestern  coast  of  Africa. 
At  Tangier  in  Africa  it  swept  the  coast  as  a  very  high 
wave  no  less  than  eighteen  times,  or,  in  other  words, 
eighteen  huge  waves  rolled  in  from  the  ocean.  At  Fun- 
chal,  on  the  Madeira  Islands,  this  wave  rose  fifteen  feet 
above  the  high  water  mark. 

Many  attempts  have  been  made  to  explain  the  manner 
in  which  the  great  sea  waves  are  started  in  earthquake 
movements.  Some  believe  that  they  are  due  to  the  sudden 
raising  or  heaving  up  of  the  water,  far  above  ordinary 
level.  But,  as  Lyell  points  out,  this  explanation  would 
not  be  satisfactory  for  the  waves  produced  in  the  case  of 
the  Lisbon  earthquake,  since  it  would  fail  to  account  for 
the  fact  that  both  on  the  coasts  of  Portugal  as  well  as  on 
the  island  of  Madeira  the  high  wave  was  preceded  by  a 
movement  of  the  water  toward  the  point  of  origin;  that 
is,  the  waters  moved  away  from  Lisbon  and  the  Madeira 
Islands,  so  as  to  leave  the  water  very  low  at  those  points, 
when  shortly  afterwards  a  huge  wave  rushed  in  from 
the  sea  and  swept  over  the  land. 

Earthquake  waves  move  much  more  rapidly  through 
the  solid  rocks  of  the  earth's  crust  than  through  the  waters 
of  the  ocean.  The  shock  transmitted  through  the  solid 
earth  from  Lisbon  to  the  Madeira  Islands  took  only 
twenty-five  minutes  to  reach  the  islands,  while  the  waves 
in  the  ocean  took  about  two  and  a  half  hours  to  cover 
the  same  distance. 


CHAPTER  XXVII 

THE  EARTHQUAKE  OF  CUTCH,  INDIA,  IN  1819 

Cutch  is  one  of  the  Provinces  of  India  lying  on  the  west- 
ern coast  of  Hindostan,  east  of  the  delta  of  the  Indus 
River. 

A  great  earthquake  occurred  in  this  region  on  June  16th, 
1819.  As  indicated  by  the  map  presented  in  Fig.  44,  by 
Lyell,  the  district  of  Cutch  lies  on  the  coast  of  the  Arabian 
Sea.  Cutch  is  at  times  a  peninsula,  being  washed  on  the 
south  and  east  by  the  Arabian  Sea  and  the  Gulf  of  Cutch, 
and  on  the  north  by  a  depression  known  as  the  Runn  of 
Cutch  which,  during  unusual  tides,  is  overflowed  by  the 
waters  of  the  sea,  but  for  the  rest  of  the  year  is  dry. 

The  earthquake  of  Cutch  was  apparently  central  at 
the  town  of  Bhooj,  where  the  destruction  was  extreme, 
hardly  a  house  being  left  standing.  The  shock  extended 
over  a  radius  of  about  1,000  miles  from  Bhooj,  reaching 
to  Khatmandoo,  Calcutta,  and  Pondicherry. 

At  Anjar  the  fort,  together  with  its  tower  and  guns, 
were  completely  ruined.  The  shocks  continued  at  inter- 
vals after  the  principal  shock  until  June  20th,  when  the 
volcano  of  Denodur  is  said  by  some  to  have  emitted  flames, 
although  this  is  denied  by  others. 

Great  changes  were  produced  in  the  eastern  channel  of 
the  Indus,  which  forms  the  western  boundary  of  the  Prov- 
ince of  Cutch.  The  water  in  this  inlet  had  become  so 
low  that  it  was  readily  fordable  at  low  tide  at  Luckput, 
and  was  only  covered  with  six  feet  of  water  at  high  tide. 
Q  [257] 


258         VOLCANOES  AND  EARTHQUAKES 

After  the  earthquake  it  deepened  at  the  port  of  Luckput 
to  over  eighteen  feet  at  low  tide,  while  in  other  parts  of 
the  channel  the  water  had  deepened  from  four  to  ten  feet 
at  high  tide,  where  before  the  earthquake  shock  it  had 
never  been  deeper  than  from  one  to  two  feet.  Indeed, 


Map  of  the  countries 
at  the  Mouth  of  the 
Indi 


X      Mud  Volcanoes. 

Area  submerged  during  earthquake. 
HA     The  Runn,  alternately  land  and  water. 


FIG.  44.   MAP  SHOWING  DISTRICT  VISITED  BY  THE  EARTHQUAKE  OF  CUTCH 
OP  1819 

after  these  changes  the  inland  navigation  of  the  country 
again  became  possible  after  having  been  closed  for  many 
centuries. 

The  Cutch  earthquake  resulted  in  a  marked  depression 
of  the  country,  especially  north  of  Luckput,  where  the 


EARTHQUAKE  OF  CUTCH 


259 


fort  and  village  of  Sindree  were  so  quietly  sunk  that  the 
fort,  with  its  tower  and  walls,  was  left  projecting  slightly 
above  a  body  of  water  that  not  only  completely  covered 
the  old  site  but  also  formed  a  large  lake  marked  on  the 
preceding  map,  at  Sindree,  by  the  dark  shading.  It  was 
this  change  of  level  that  deepened  the  eastern  channel 
of  the  Indus,  just  mentioned. 

Fig.  45,  from  Lyell,  gives  an  idea  of  the  appearance  of 


FIG.  45.     SINDREE  BEFORE  THE  EARTHQUAKE  OF  1819 

the  fort  at  Sindree  before  the  earthquake.  The  appearance 
of  the  fort  after  its  submergence  is  represented  in  Fig.  46, 
where,  as  will  be  noticed,  only  the  top  of  the  tower  and 
the  walls  remain  above  the  surface  of  the  water.  That  the 
masonry  was  not  affected  either  by  the  earthquake,  or 
by  the  inrush  of  waters,  is  evident  from  the  fact  that  the 
ruins  were  still  standing  in  March,  1838,  as  represented 
in  the  figure. 


260         VOLCANOES  AND  EARTHQUAKES 

In  heavy  shading  on  the  map  in  Fig.  44  is  a  large  area 
lying  in  the  northern  part  of  the  province  known  as  the 
Runn  of  Cutch.  This  is  a  flat  region  of  about  7,000  square 
miles.  It  owes  its  level  surface  to  its  being  the  deserted 
or  dried-up  bed  of  a  sea.  For  the  greater  part  of  the  year 
its  bottom  is  dry  and  hard,  and  is  covered  with  a  crust  of 
salt  half  an  inch  or  so  in  thickness. 

According  to  Lyell,  from  whom  most  of  the  facts  con- 


__ 


FIG.  46.    SINDREE  AFTER  THE  EARTHQUAKE  OF  1819 

cerning  this  earthquake  have  been  obtained,  the  Runn 
of  Cutch  is  connected  with  a  vast  inland  sea,  not  only  by 
the  water  driven  into  it  through  the  Gulf  of  Cutch,  but 
also  through  the  eastern  channel  of  the  Indus  at  Luckput. 
These  changes  occur  especially  during  the  monsoon,  when 
the  seas  are  high,  and  especially  after  the  heavy  rains  that 
come  with  these  winds,  when  the  wet  condition  of  the 
soil  permits  the  sea  water  to  spread  rapidly. 

Traditions  of  the  natives  tend  to  confirm  belief  that 
Cutch  a  long  time  ago  was  a  true  peninsula,  and  that  the 
Runn  of  Cutch  was  then  an  arm  of  the  sea. 

That  a  change  of  this  character  did  occur  in  the  Runn 
of  Cutch  seems  to  be  proved  by  the  ruins  of  old  towns 
now  far  inland  that  are  said  to  have  been  ancient  sea- 


EARTHQUAKE  OF  CUTCH  261 

ports,  and  as  apparent  evidences  of  this  many  pieces  of 
wrought  iron  and  ships'  nails  have  been  found  in  parts 
of  the  Runn. 

At  the  same  time  that  the  sinking  of  the  land  around 
the  fort  and  village  of  Sindree  took  place  a  considerable 
elevation  occurred  in  the  neighborhood.  Immediately 
after  the  earthquake,  the  people  in  Sindree  saw  that  a  low 
hill  or  mound  had  been  thrown  up  in  a  place  that  before 
had  been  a  low  and  perfectly  level  plain.  They  named 
this  elevation  the  Ullah  Bund,  or  the  Mound  of  God,  in 
order  to  distinguish  it  from  several  embankments  that 
had  been  built  directly  across  the  eastern  mouth  of  the 
Indus;  for  the  Ullah  Bund  had  been  raised  by  the  earth- 
quake across  the  same  branch  of  the  Indus. 

For  several  years  after  the  earthquake  of  1819  marked 
changes  kept  developing  in  the  channels  of  the  Indus. 
During  1826  a  large  body  of  water  entered  into  the  eastern 
branch  of  the  Indus  above  the  Ullah  Bund  and  finally 
forced  its  way  through  the  mound,  thus  establishing  a 
direct  course  to  the  sea.  The  Ullah  Bund,  being  thus 
cut  in  two,  an  opportunity  was  afforded  of  seeing  the 
materials  of  which  it  was  composed.  These  were  found 
to  consist  principally  of  clay  filled  with  shells. 

The  opening  of  the  river  resulted  in  throwing  such 
large  quantities  of  fresh  water  into  Lake  Sindree  that  its 
waters  were  rendered  fresh  for  several  months,  but  at 
last  regained  their  saltiness. 

Dana  states  that  in  1845  another  earthquake  occurred 
in  this  district  which  converted  Sindree  Lake  into  a  salt 
marsh. 


CHAPTER  XXVIII 

THE  SAN  FRANCISCO  EARTHQUAKE  OF  APRIL  18,   1906 

About  twelve  minutes  past  five  o'clock  on  the  morning 
of  the  18th  of  April,  1906,  the  inhabitants  of  San  Francisco 
were  rudely  awakened  by  a  few  frightful  earthquake 
shocks.  Their  houses  were  violently  shaken  to  and  fro, 
and  on  all  sides  were  heard  the  awful  crashings  of  falling 
walls,  chimneys,  and  buildings,  together  with  the  death- 
shrieks  of  those  caught  in  the  ruins.  Rushing  madly 
into  the  streets  they  could  see  on  every  side  evidences  of 
destruction;  for,  in  almost  every  direction,  were  heaps  of 
fallen  buildings,  still  being  violently  shaken  by  the  earth- 
quake waves  that  rapidly  passed  through  the  solid  earth. 
Huge  cracks  or  crevices  had  been  formed  in  the  streets, 
while  the  heavy  rails  of  the  trolley  tracks  had  been  bent 
and  twisted  by  the  mighty  forces. 

Before  describing  in  detail  the  great  San  Francisco 
earthquake,  the  location  of  the  city  and  its  surroundings 
demand  consideration. 

As  can  be  seen  from  the  map,  Fig.  47,  San  Fran- 
cisco is  situated  on  the  western  coast  of  California,  at 
the  northern  end  of  a  peninsula,  some  twenty  miles  in 
length  and  about  six  miles  in  width.  This  peninsula  is 
formed  by  the  magnificent  Bay  of  San  Francisco  on  the 
east,  a  navigable  strait  called  the  Golden  Gate  on  the  north, 
and  the  Pacific  Ocean  on  the  west. 

San  Francisco  Bay,  accessible  by  the  Golden  Gate,  is 
the  principal  harbor  on  the  Pacific  Coast,  and  is,  indeed, 
[262] 


SAN  FRANCISCO  EARTHQUAKE 


263 


FIG.  47.     MAP  OF  WESTERN  COAST  OF  CALIFORNIA 
SHOWING  POSITION  OF  SAN  FRANCISCO 

one  of  the  most  magnificent  harbors  in  the  world.  It  is 
land-locked,  that  is,  surrounded  by  a  continuous  land 
border  except  at  its  entrance  through  the  Golden  Gate. 
Including  San  Pablo  Bay,  it  has  a  length  of  about  fifty- 


264         VOLCANOES  AND  EARTHQUAKES 

five  miles,  and  varies  in  breadth  from  three  to  twelve 
miles.  The  entrance  to  the  harbor,  however,  is  impeded 
by  a  bar  across  the  mouth  of  the  Golden  Gate,  over  which 
there  is  a  depth  of  but  thirty  feet  of  water  at  low  tide. 

San  Francisco  has  over  750  miles  of  streets,  200  miles 
of  which  are  paved.  The  city  is  lighted  by  both  electricity 
and  gas,  and  has  an  extensive  system  of  water-works, 
the  water  being  brought  from  the  Pilarcitos  and  Calaveras 
Creeks,  situated  from  twenty  to  forty  miles  respectively 
from  the  city. 

San  Francisco  is  in  a  region  where  earthquakes  are  com- 
mon. It  might,  therefore,  be  visited  at  any  time  by  a 
great  catastrophe.  There  have  occurred  between  1850 
and  1888,  no  less  than  254  earthquake  shocks  in  the  State 
of  California,  these  shocks  having  been  especially  frequent 
in  the  country  surrounding  San  Francisco  Bay.  The 
most  severe  were  the  earthquake  of  1868,  which  injured 
San  Francisco;  the  Owens  Valley  earthquake  of  1872; 
the  Vacaville  earthquake  of  1892;  the  Mare  Island  earth- 
quake of  1898;  and  a  smaller  earthquake  in  1900.  Since 
1900  there  was  a  period  of  rest  until  the  18th  of  April, 
1906. 

As  in  the  case  of  practically  all  severe  earthquakes, 
that  which  destroyed  San  Francisco  consisted  of  a  few 
momentary  shocks:  then  all  was  over.  According  to  a 
preliminary  report  of  the  State  Earthquake  Commission, 
appointed  by  the  Governor  of  California,  April  21st,  1906, 
these  shocks,  as  recorded  in  the  observatory  at  Berkeley, 
began  at  twelve  minutes  and  six  seconds  after  five  A.  M., 
Pacific  Standard  Time.  Their  entire  duration  was  only 
one  minute  and  fifty  seconds,  but,  as  frequently  happens, 
there  were  a  number  of  minor  shocks,  following  at  regular 
intervals  during  the  next  few  hours  as  well  as  the  next 
few  days. 


SAN  FRANCISCO  EARTHQUAKE  265 

While  the  most  severe  shocks  were  in  the  neighborhood 
of  the  Peninsula  of  San  Francisco,  yet  minor  disturbances 
were  felt  as  far  north  as  Coos  Bay,  Oregon,  and  as  far 
south  as  Los  Angeles,  California.  As  shown  by  recording 
instruments  at  the  seismograph  station  at  Washington, 
D.  C.,  Sitka,  Alaska;  Potsdam,  Germany;  and  Tokio, 
Japan,  a  series  of  waves  were  propagated  through  the 
earth,  as  well  as  over  its  periphery. 

The  damage  done  within  the  city  limits  was  wide-reach- 
ing. Among  the  buildings  almost  completely  destroyed 
were  the  City  Hall,  on  which  about  $7,000,000  had  been 
expended,  the  United  States  Post  Office,  besides  many 
business  blocks,  hotels,  department  stores,  theatres, 
banks,  churches,  and  dwelling  houses. 

Amid  the  terrors  of  such  a  calamity  it  is  difficult  to 
obtain  observations  possessing  any  scientific  value. 
Fortunately,  however,  there  was  in  the  city  a  physicist 
trained  to  observe  phenomena  of  this  character,  Professor 
George  Davidson  of  the  University  of  California.  Like 
others,  he  had  been  awakened  by  the  first  severe  shock. 
At  once  recognizing  the  nature  of  the  phenomenon,  and 
desirous  of  obtaining  the  exact  time  of  its  occurrence,  he 
counted  seconds  while  he  ran  towards  the  table  on  which 
he  had  placed  his  watch,  and  in  this  way  estimated  that 
the  shock  occurred  at  twelve  minutes  past  five  in  the  morn- 
ing. The  closeness  of  this  observation  is  emphasized  by 
the  fact  that  it  differed  from  the  recorded  time  by  only 
six  seconds.  He  states  that  the  motion,  at  the  time  of 
its  greatest  intensity,  closely  resembled  that  of  a  rat 
vigorously  shaken  by  a  terrier. 

The  destruction  caused  by  the  earthquake  was,  how- 
ever, but  a  small  part  of  the  total  loss  to  the  city.  Fires 
were  almost  immediately  started  in  the  ruined  houses  by 
the  fires  in  the  kitchens  and  other  parts  of  the  houses,  by 


266         VOLCANOES  AND  EARTHQUAKES 

the  ignited  jets  of  the  illuminating  gas,  and,  perhaps, 
especially,  by  the  crossing  of  numerous  electric  light  wires. 

The  manner  in  which  the  woodwork  and  other  com- 
bustible materials  of  the  buildings  were  loosely  tossed 
together  by  the  shocks  helped  the  quick  spread  of  the 
fires,  and  this,  too,  was  probably  greatly  aided  by  the 
illuminating  gas  from  the  broken  gas  pipes  and  mains. 
Eight  severe  conflagrations  were,  therefore,  soon  raging 
in  different  parts  of  the  doomed  city.  What  made  these 
fires  especially  dangerous  was  the  fact  that  the  earthquake 
shocks  had  destroyed  the  water  pipes.  Thus  the  firemen 
were  handicapped  in  their  heroic  endeavors  to  extinguish 
the  flames. 

At  the  time  of  the  fire  a  strong  wind  was  blowing  from 
the  northeast.  Since  the  firemen  were  unable  to  check 
the  flames,  the  fire  line  rapidly  advanced.  Its  path  led 
towards  the  best  residential  parts  of  the  city  through 
portions  of  the  mission  section  containing  a  dense  popula- 
tion of  poor  people.  The  dwellings  in  this  latter  section 
consisted  of  frame  houses,  through  which  the  flames 
rapidly  spread. 

There  was  but  one  way  to  save  the  city  from  total  de- 
struction— a  free  use  of  dynamite!  This  was  intelligently 
employed  until  the  supply  gave  out,  when  it  seemed  that 
the  city  was  doomed  to  utter  destruction.  But  at  the  last 
moment,  as  it  were,  came  a  lucky  change  in  the  direction 
of  the  wind.  Instead  of  blowing  from  the  northeast, 
the  steady  southwest  winds  set  in,  and  beat  back  the 
fire  on  itself,  so  by  Friday,  the  18th  being  Wednesday, 
it  was  under  complete  control  and  the  rest  of  the  city 
was  saved. 

The  extent  of  the  fire  is  thus  described  in  an  article  in 
the  "  Outlook,"  for  Saturday,  April  28th,  1906,  as  follows: 

"The  turn  in  the  direction  of  the  fire  endangered  for  a 


From  a  Stereograph,  Copyright,  1906,  by  Underwood  &  Underwood 

A  SAN  FRANCISCO  PAVEMENT  TOHN  BY  THE  EARTHQUAKE 


SAN  FRANCISCO  EARTHQUAKE  267 

time  the  great  Ferry  House,  at  the  foot  of  Market  Street. 
While  the  section  actually  destroyed  is  not,  geographic- 
ally speaking,  much  more  than  one-third  of  the  city  limits, 
yet  it  is  in  the  heart  of  San  Francisco,  and  includes  the 
chief  business  streets  and  the  Mission  District,  inhabited 
by  poor  people,  and  a  large  part  of  the  so-called  Nob  Hill 
Quarter,  where  were  the  finest  and  costliest  residences  of 
the  city.  Another  fine  residence  section,  Civic  Heights, 
escaped,  together  with  that  known  as  the  Western  Dis- 
trict. 

"The  unburned  district,  though  large  in  extent,  was  in 
the  nature  of  suburbs,  and  was  not  closely  built  up,  so 
that  estimates  made,  as  late  as  Saturday,  declared  that 
three-fourths  of  San  Francisco's  improvements  in  real 
estate  had  been  destroyed." 

The  burnt  district  was  about  two  miles  from  east  to 
west  and  from  two  to  four  miles  from  north  to  south, 
with,  of  course,  very  irregular  outlines. 

Naturally,  the  great  destruction  wrought  by  the  earth- 
quake of  April  18th,  1906,  attracted  the  almost  universal 
attention  of  scientific  men  especially  interested  in  earth- 
quake phenomena.  We  are,  therefore,  able  to  speak 
authoritatively  about  the  probable  causes. 

The  great  San  Francisco  earthquake  of  April  18th, 
1906,  appears  to  have  been  a  tectonic  quake.  Ransome, 
in  an  article  entitled,  "The  Probable  Cause  of  the  San 
Francisco  Earthquake,"  says: 

"The  region  thus  amply  fulfils  the  conditions  under 
which  tectonic  earthquakes  arise.  It  is  in  unstable  equilib- 
rium, and  it  is  cut  by  long  northwest  faults  into  narrow 
blocks  which  are  in  turn  traversed  by  many  minor  dis- 
locations. Under  the  operation  of  the  unknown  forces  of 
elevation  and  subsidence,  stresses  are  set  up  which  finally 
overcome  the  adhesion  of  the  opposing  walls  of  one  or 


268         VOLCANOES  AND  EARTHQUAKES 

more  of  the  fault  fissures;  an  abrupt  slip  of  a  few  inches, 
or  a  few  feet,  takes  place  and  an  earthquake  results. 
The  region  extending  for  some  hundreds  of  miles  north  and 
south  of  the  Bay  of  San  Francisco  may  be  considered  as 
particularly  susceptible  to  shocks  on  account  of  the 
number  and  magnitude  of  the  faults  and  the  evidences 
that  these  furnish  of  very  recent  slippings  and  the  marked 
subsidence  in  the  vicinity  of  the  Golden  Gate." 


CHAPTER  XXIX 

SOME  OTHER  NOTABLE  EARTHQUAKES 

It  would,  of  course,  be  impossible  within  the  limits  of 
this  book  to  attempt  a  description  of  all  the  remarkable 
earthquakes  in  the  annals  of  science;  but  before  leaving 
this  part  of  the  theme  a  brief  account  of  a  few  more  among 
the  many  may  be  worth  while. 

Jamaica,  one  of  the  West  Indian  Islands,  about  ninety 
miles  south  of  Cuba,  suffered  a  very  destructive  earth- 
quake in  1692.  During  this  earthquake  the  ground  was 
agitated  like  the  waves  of  the  sea.  These  movements 
were  so  violent  that  numerous  fissures  were  made  in  the 
ground,  as  many  as  300  being  formed  at  the  same  time, 
rapidly  opening  and  closing.  Many  of  the  inhabitants 
were  swallowed  up  in  these  fissures.  In  some  cases, 
however,  their  bodies  were  afterward  thrown  out  of  the 
fissures,  along  with  quantities  of  water. 

The  Jamaican  earthquake  was  characterized  by  marked 
sinkings  of  the  ground.  At  the  city  of  Port  Royal,  which 
was  then  the  capital,  many  houses  on  the  harbor  side 
sank  in  from  twenty-four  to  forty-eight  feet  of  water. 
As  in  the  case  of  the  earthquake  at  Cutch,  many  of  these 
houses  were  left  standing,  the  chimney  tops  of  some 
being  seen  above  the  water,  with  their  foundations  and 
other  parts  apparently  uninjured,  and  some  of  them 
were  standing  at  a  date  as  late  as  1780.  At  a  little  later 
date,  1793,  they  were  mostly  ruins. 

During  the  Jamaican  quake  a  tract  of  land  containing 
[269] 


270         VOLCANOES  AND  EARTHQUAKES 

at  least  1,000  acres  near  the  town  was  sunk,  and  a  wave 
of  the  sea  rolled  over  it.  This  wave  is  said  by  Lyell  to 
have  carried  a  frigate  over  the  roofs  of  the  houses  and  left 
it  stranded  on  one  roof.  When  the  wave  rolled  back  to 
the  sea,  the  weight  of  the  frigate  made  it  fall  through 
the  roof. 

Perhaps  one  of  the  most  remarkable  things  about  the 
Jamaican  earthquake  was  the  swallowing  up  of  several 
plantations,  which  disappeared,  together  with  all  their 
inhabitants,  their  former  place  becoming  a  lake.  But 
the  lake  soon  disappeared,  leaving  a  mass  of  sand  and 
gravel  which  obliterated  any  least  sign  that  dwellings  and 
trees  had  once  adorned  the  spot. 

The  forces  developed  during  this  earthquake  were  suffi- 
ciently powerful  to  make  several  rents  in  the  Blue  Moun- 
tains, and  the  shock  of  blows  on  the  waters  of  the  sea 
killed  fish  by  the  hundred  thousands  so  that  the  silver 
shine  of  their  dead  bodies  stretched  for  miles  and  was 
beheld  for  days  "  on  the  face  of  the  deep." 

Portions  of  the  world  that  have  been  frequently  visited 
by  mighty  earthquakes,  are  the  coasts  of  Chile.  On  the 
24th  of  May,  1751,  a  part  of  the  Chilian  coast  near  the 
ancient  town  of  Conception,  sometimes  called  Penco, 
was  destroyed  by  an  earthquake,  and  the  powerful  earth- 
quake waves  that  afterwards  rushed  in  from  the  sea. 
So  complete  was  this  destruction  that  the  ancient  harbor 
was  rendered  useless  and  the  people  had  to  build  another 
town  about  ten  miles  from  the  coast,  so  as  to  be  beyond 
the  reach  of  earthquake  waves  from  the  sea. 

Another  great  earthquake  occurred  on  the  coast  of 
Chile  on  the  19th  of  November,  1822.  This  shock  was  felt 
simultaneously  over  a  distance  of  1,200  miles  from  north 
to  south.  It  reached  its  greatest  intensity  about  100 
miles  north  of  Valparaiso.  This  earthquake  caused  a 


OTHER  NOTABLE  EARTHQUAKES         271 

rising  of  the  coast  to  a  height  of  from  three  to  five  feet. 
From  careful  examinations  it  appears  that  the  area  over 
which  a  permanent  elevation  of  the  country  took  place 
must  have  been  equal  to  100,000  square  miles,  an  area 
equal  to  about  half  of  the  area  of  France,  and  five-sixths 
that  of  Great  Britain  and  Ireland. 

"If  we  suppose,"  says  Dana,  "the  elevation  to  have 
been  only  three  feet  on  an  average,  it  will  be  seen  that  the 
mass  of  rock  added  to  the  continent  of  America  by  the 
movement,  or,  in  other  words,  the  mass  previously  below 
the  level  of  the  sea,  and  after  the  shock,  permanently 
above  it,  must  have  contained  fifty-seven  cubic  miles 
in  bulk;  which  would  be  sufficient  to  form  a  conical  moun- 
tain two  miles  high  (or  about  as  high  as  Etna)  with  a 
circumference  at  the  base  of  nearly  thirty-three  miles. 
.  .  .  Assuming  the  Great  Pyramid  of  Egypt,  if  solid, 
to  weigh  in  accordance  with  the  estimate  before  given 
6,000,000  tons,  we  may  state  that  the  rock  added  to  the 
continent  by  the  Chilian  earthquake  would  have  equalled 
more  than  100,000  pyramids." 

"But  it  must  always  be  borne  in  mind  that  the  weight 
of  rock  here  alluded  to  constituted  but  an  insignificant 
part  of  the  whole  amount  which  the  volcanic  forces  had 
to  overcome.  The  thickness  of  rock  between  the  surface 
of  Chile  and  the  subterranean  foci  of  volcanic  action  may 
be  many  miles  or  leagues  deep.  Say  that  the  thickness 
was  only  two  miles,  even  then  the  mass  which  changed 
place  and  rose  three  feet,  being  200,000  cubic  miles  in 
volume,  must  have  exceeded  in  weight  363,000,000 
pyramids." 

The  shocks  of  this  earthquake  continued  from  the  time 
of  its  occurrence,  on  November  19th,  1822,  to  the  end  of 
September,  1823,  and  even  then  there  were  scarcely  two 
days  that  passed  without  a  shock. 


272         VOLCANOES  AND  EARTHQUAKES 

On  the  20th  of  February,  1835,  the  same  part  of  the 
world  was  in  the  throes  of  an  earthquake  that  was  felt 
nearly  1,000  miles  from  north  to  south,  or  from  near  the 
town  of  Concepcion  to  the  Isle  of  Chiloe,  and  from  east 
to  west  a  distance  of  about  500  miles,  from  Mendoza  to 
the  island  of  Juan  Fernandez,  which  you  probably  know 
better  as  Robinson  Crusoe's  Island.  By  this  earthquake 
the  new  town  of  Concepcion  and  several  other  towns 
were  partly  destroyed. 

There  were  the  same  phenomena  connected  with  great 
sea  waves  that  are  common  in  earthquakes  of  this  char- 
acter. Both  this  and  the  preceding  earthquakes  probably 
began  on  the  bed  of  the  ocean  at  some  distance  from  the 
coast;  for,  in  the  last  earthquake,  the  sea  retired  from 
the  Bay  of  Concepcion  and  vessels  were  grounded  that  had 
been  anchored  in  seven  fathoms  of  water.  Shortly  after- 
wards waves  from  sixteen  to  twenty  feet  in  height  rushed 
in  from  the  ocean  and  swept  over  the  land. 

It  is  interesting  in  this  connection  to  note  that  the 
volcanoes  of  the  Chilian  Andes  were  in  an  unusual  state 
of  activity  before,  during,  and  after  the  earthquake. 

Another  characteristic  of  this  quake  was  the  great 
number  of  severe  shocks.  Between  the  day  of  the  first 
great  shock;  i.  e.,  on  February  20th,  1835,  and  March  4th, 
there  were  more  than  300  severe  shocks. 

In  this  as  in  the  preceding  quake  a  notable  elevation 
of  the  land  near  the  coast  occurred,  amounting  to  from 
four  to  five  feet,  and  a  part  of  the  bed  of  the  ocean  near 
the  coast  was  raised  permanently  above  the  level  of  the 
sea. 

In  the  description  of  the  explosive  eruption  of  Kra- 
katoa  in  1883,  the  fact  was  noted  that  the  island  of 
Java  is  very  frequently  visited  by  earthquakes.  Here 
a  terribly  severe  earthquake  occurred  on  the  5th  of 


OTHER  NOTABLE  EARTHQUAKES       273 

January,  1699.  There  were  no  less  than  208  shocks  of 
great  intensity.  Considerable  property  in  the  city  of 
Batavia  was  destroyed,  and  a  neighboring  river,  that  has 
its  head  waters  by  a  volcano  near  the  city,  ran  high  and 
muddy  and  brought  down  multitudes  of  fishes  that  had 
been  killed,  together  with  many  buffaloes,  tigers,  rhinoce- 
roses, deer,  and  other  wild  beasts.  Seven  hills  bordering 
on  the  river  sank  down,  damming  up  the  streams  of  the 
region  and  thereby  causing  wide  destruction  from  floods. 

During  portions  of  the  years  1811  and  1812  an  earth- 
quake occurred  in  the  United  States,  in  the  Mississippi  Val- 
ley near  the  town  of  New  Madrid,  Missouri,  at  the  mouth  of 
the  Ohio  River.  These  shocks  continued  almost  inces- 
santly for  several  months,  and  were  accompanied  by  a 
sinking  of  the  ground  over  large  areas.  This  depressed 
area,  known  in  the  neighborhood  as  The  Sunk  Country, 
extended  along  the  course  of  the  White  Water  River  and 
its  tributaries  for  a  distance  of  about  eighty  miles  from 
north  to  south,  and  several  miles  from  east  to  west.  Most 
of  it  was  converted  into  a  marshy  lake  characterized  by 
thousands  of  submerged  trees.  The  area  was  covered 
for  the  greater  part  with  water  to  a  depth  of  about  three 
to  four  feet. 

As  the  earthquake  shocks  continued  at  intervals  for 
several  months  there  was  an  ample  opportunity  for  study- 
ing the  peculiarities  of  the  earth  waves.  The  ground 
rose  and  fell  like  large  waves  in  the  sea,  and  after  the 
crest  of  the  waves  had  reached  great  heights,  the  ground 
burst,  and  threw  large  quantities  of  water,  sand,  and  earth 
into  the  air. 

Throughout  the  disturbed  district  there  were  numerous 

depressions  known   as  sink-holes,  or  irregularly  shaped 

pits,  varying  from  ten  to  thirty  yards  across,  and  having 

a  depth  of  about  twenty  feet.     These  were  formed  by 

R 


274         VOLCANOES  AND  EARTHQUAKES 


OTHER  NOTABLE  EARTHQUAKES        275 

the  forcible  ejection  of  large  quantities  of  water  mixed 
with  sand. 

New  Zealand  has  been  subject  to  earthquake  shocks 
for  a  long  time,  the  years  1826,  1841,  1843,  1848,  and 
1855  being  especially  marked  by  such  visitations.  It 
is  a  characteristic  of  the  New  Zealand  earthquakes  that 
they  have  produced  a  marked  change  in  the  coast  line. 
This  was  particularly  the  case  with  those  of  1848  and 
1855. 

The  23d  of  January,  1855,  an  earthquake  occurred 
that  was  most  violent  in  the  narrowest  part  of  Cook's 
Strait,  a  body  of  water  separating  the  two  principal  isl- 
ands that  constitute  New  Zealand;  or,  as  they  are  called, 
the  North  Island  and  the  South  Island.  These  shocks 
were  felt  at  sea  by  ships  150  miles  from  the  coast.  The 
entire  area  shaken,  including  the  water,  has  been  estimated 
at  three  times  the  area  of  the  British  Isles.  In  the  vicinity 
of  the  southern  shores  of  the  North  Island  a  tract  of  land 
having  an  area  of  4,600  square  miles  is  believed  to  have 
been  permanently  raised  from  one  to  nine  feet. 

The  earthquakes  in  New  Zealand  are  evidently  of  the 
tectonic  type.  During  that  of  1848  a  rent  or  fissure  was 
formed,  which,  though  but  eighteen  inches  in  average 
width,  yet  extended  for  a  distance  of  sixty  miles  in  a 
direction  parallel  to  one  of  the  mountain  chains. 

On  the  31st  of  August,  1886,  an  earthquake  of  consider- 
able intensity  occurred  in  the  United  States  in  the  neigh- 
borhood of  the  city  of  Charleston,  South  Carolina.  The 
details  of  this  earthquake  were  carefully  studied  by  Major 
Button  of  the  U.  S.  A.,  and  published  in  the  Ninth  Annual 
Report  of  the  United  States  Geological  Survey  of  1888. 

Charleston  is  situated  on  a  narrow  tongue  of  land 
between  the  Ashley  and  the  Cooper  Rivers,  about  seven 
miles  from  the  Atlantic  Ocean.  There  are  in  this  area 


276         VOLCANOES  AND  EARTHQUAKES 

numerous  creeks  connected  with  the  drainage  of  these 
rivers.  As  the  city  limits  extended,  the  creeks  were  filled 
in,  forming  "made  land,"  all  buildings  or  structures 
erected  on  this  land  being  supported  by  pilings. 

It  appears  that  the  point  at  which  the  earthquakes 
started  was  situated  sixteen  or  seventeen  miles  from 
Charleston. 

The  earthquake  shock  affected  a  large  area  of  the  United 
States.  Fig.  49  shows  curved  lines  called  isoseismal  con- 
necting places,  having  the  same  degree  of  seismic  intensity. 
This  map  shows  that  these  isoseimals  are  marked  by 
figures  or  numbers  from  two  to  ten.  These  numbers  are 
the  numbers  of  the  Rossi-Forel  earthquake  scale.  They 
indicate  varying  degrees  of  intensity,  beginning  from  the 
least  intense  shock  which  is  marked  as  two  and  ending 
with  the  severest  shock  marked  as  ten.  There  is  one 
degree  not  marked  on  this  map,  the  least,  called  the 
micro-seismic  shock. 

The  shocks  then  increase  in  intensity  as  follows:  II.  Ex- 
tremely feeble  shocks;  III.  Very  feeble  shocks;  IV.  Feeble 
shocks;  V.  Shocks  of  moderate  intensity;  VI.  Fairly  strong 
shocks;  VII.  Strong  shocks;  VIII.  Very  strong  shocks;  IX. 
Extremely  strong  shocks;  X.  Shocks  of  extreme  intensity. 

The  meaning  of  the  map  presented  in  the  accompanying 
figure  will  now  become  more  apparent  in  several  ways. 
That  portion  numbered  ten,  denoting  where  shocks  of 
greatest  intensity  have  been  experienced,  clearly  indicates 
the  region  just  above  the  point  where  the  earthquake 
originated. 

Beyond  this  is  a  region  marked  nine  where  the  earth- 
quake shock  has  decreased  in  intensity  to  the  next  figure 
on  the  Rossi-Forel  scale,  and  then  to  eight  and  a  half, 
seven,  six,  five,  four,  three,  and  two. 

The  Charleston  earthquake  damaged   property  to  a 


OTHER  NOTABLE  EARTHQUAKES  277 


FIG.  49.     MAP  SHOWING  REGION  AFFECTED  BY  THE  CHARLESTON 
EARTHQUAKE  OF  1886 


278         VOLCANOES  AND  EARTHQUAKES 

considerable  extent;  for,  although  comparatively  few 
buildings  were  completely  destroyed,  a  considerable 
number  were  partially  injured,  and  many,  not  thrown 
down  by  the  shock,  had  to  be  torn  down  in  order  to  insure 
public  safety.  The  loss  of  life,  fortunately,  was  compara- 
tively small.  During  this  earthquake  a  number  of  open- 
ings called  craterlets  were  made  in  the  ground  by  the 
forcible  ejection  of  large  quantities  of  water  and  sand. 

The  empire  of  Japan  is  another  part  of  the  world  par- 
ticularly subject  to  great  as  well  as  frequent  earthquake 
shocks.  Although  Japan  is  also  especially  noted  for  its 
volcanic  activity,  its  earthquakes  are  almost  entirely  of 
the  tectonic  type,  or  are  due  to  the  slipping  of  the  land 
at  faults  in  the  earth's  crust.  Most  of  these  quakes  occur 
on  the  bed  of  the  ocean  on  the  sides  of  a  steep  slope  that 
extends  down  to  a  very  deep  part  of  the  Pacific  known 
as  the  Tuscarora  Deep. 

On  the  28th  of  October,  1891,  Japan  was  visited  by  a 
great  quake,  generally  known  as  the  Mino-Owaro  earth- 
quake, from  the  name  of  the  two  provinces  of  Mino  and 
Owaro  in  which  it  occurred. 

This  earthquake  is  correctly  regarded  as  one  of  the  most 
severe  in  Japanese  records.  Originating,  as  it  did,  in  a 
densely  populated  section,  it  caused  a  great  loss  of  life 
and  property.  The  deaths  reached  about  7,000,  while 
the  number  of  houses  entirely  destroyed  reached  about 
80,000  and  those  partly  destroyed  nearly  200,000.  The 
total  area  markedly  affected  reached  250,000  square 
kilometres,  while  the  area  sensibly  affected  reached 
900,000  square  kilometres,  or  a  little  more  than  one-half 
the  Empire. 

The  place  at  which  this  earthquake  started  was  situated, 
not  as  usual  on  the  bed  of  the  ocean,  but  on  the  surface 
of  the  land.  The  first  shock  was  the  strongest  and  wrought 


OTHER  NOTABLE  EARTHQUAKES         279 

the  greatest  havoc.  Besides  the  loss  of  life  and  property, 
the  damage  to  the  system  of  dikes  or  levees  on  the 
river  where  it  passed  through  the  delta  plain  near  the 
river's  mouth  was  heavy,  and  singular  in  some  of  its 
features.  In  one  case,  near  the  city  of  Nagoya,  on  the 
Bay  near  the  southern  coast  of  Niphon,  one  of  these 
levees  was  lifted  and  shifted  bodily  more  than  sixty  feet 
from  its  original  position. 

That  this  quake  was  of  the  tectonic  type  was  evident 
from  the  great  fault  that  was  formed.  According  to 
Davison  this  fault  was  seventy  miles  in  length  and  in 
places  had  a  breadth  of  from  two  to  five  feet.  It  ex- 
tended from  east  to  west,  crossing  the  entire  width  of  the 
island. 

Another  great  earthquake  was  that  which  hit  northeast- 
ern Bengal  and  Assam  in  India  on  the  12th  of  June,  1897. 
According  to  the  India  Geological  Survey,  by  whom  a 
careful  examination  of  the  effects  produced  by  this  quake 
was  made,  it  was,  perhaps,  the  greatest  quake  that  ever 
happened,  not  even  excepting  the  Lisbon  earthquake. 

The  place  where  the  quake  started  appears  to  have  been 
of  unusual  size  and  irregularity  of  outline.  Its  southern 
boundary  was  almost  in  the  shape  of  a  straight  line  ex- 
tending from  east  to  west  about  200  miles,  and  covering 
a  total  area  of  nearly  6,000  square  miles.  Over  all  this 
vast  area  the  intensity  of  the  shock  was  exceedingly 
severe.  The  total  area  perceptibly  shaken  by  the  quake 
was  about  equal  to  1,750,000  square  miles. 

That  this  quake  was  of  the  tectonic  type  became  evi- 
dent, when  several  faults  were  found  in  the  ground  after- 
wards. Some  of  these  exended  twelve  miles,  with  a 
breadth  at  places  as  great  as  thirty  feet. 

Valparaiso,  or,  as  the  name  means,  Vale  of  Paradise, 
the  second  largest  city  of  Chile  and  its  chief  seaport,  lies 


280         VOLCANOES  AND  EARTHQUAKES 

about  ninety  miles  east  of  Santiago,  the  capital,  with 
which  it  is  connected  by  a  railroad. 

This  beautiful  sea  city  is  built  at  the  base  of  a  cluster 
of  hills  about  1,600  feet  above  sea  level.  On  August  16th, 
1906,  it  was  visited  by  an  earthquake.  There  were  two 
distinct  shocks.  Contrary  to  general  rule  it  was  not  the 
first,  but  the  second  shock  that  did  the  most  damage, 
coming  about  ten  minutes  after  the  first.  As  you  will 
see  from  the  above  date  the  earthquake  of  Valparaiso 
occurred  shortly  after  the  catastrophe  of  San  Francisco. 
In  a  general  way,  its  coming  was  predicted  by  Dr.  G.  F. 
Becker  of  the  United  States  Geological  Survey,  on 
April  19th,  1906,  one  day  after  the  San  Francisco 
disaster.  Becker  published  an  article  in  the  "  New  York 
Tribune,"  in  which  he  argued  that  the  severe  shock  at 
San  Francisco,  having  occurred  on  one  part  of  the  earth- 
quake region  extending  around  the  Pacific,  would  prob- 
ably soon  affect  other  portions  of  this  region  along  the 
Pacific  coast  line  of  this  hemisphere. 

As  at  San  Francisco  fierce  fires  immediately  started 
in  the  ruins  of  the  houses,  but  the  Valparaisans  were  more 
fortunate  in  having  a  water  supply  available. 

There  were  very  many  shocks  following  the  first  two 
of  this  earthquake.  Indeed,  during  August  16th,  17th, 
18th,  and  19th,  no  less  than  380  were  noted. 

Santiago,  situated  at  the  foot  of  the  Andes,  was  also 
considerably  damaged  by  the  same  earthquake.  Esti- 
mates, probably  conservative,  put  the  total  of  dead  in 
both  cities  at  1,000  and  the  number  of  people  rendered 
homeless  temporarily,  at  100,000. 


CHAPTER  XXX 

SODOM  AND  GOMORRAH  AND  THE  CITIES  OF  THE  PLAIN 

The  eastern  border  of  the  Mediterranean  Sea  or  Syria, 
with  that  part  of  Arabia  forming  the  Sinai  Peninsula  and 
which  lies  between  the  two  northern  arms  of  the  Red  Sea, 
is  a  region  formerly  characterized  by  extreme  volcanic 
activity.  This  region  includes  the  greater  part  of  the  land 
promised,  according  to  the  Old  Testament,  to  the  Children 
of  Israel.  Through  a  large  part  of  this  region  flows  that 
historic  river,  the  Jordan,  until  it  empties  into  the  Dead 
Sea,  also  called  the  Salt  Sea,  the  Sea  of  the  Plain,  and  by 
some  Lake  Asphaltites  because  of  asphalt  or  bitumen  so 
abundant  on  its  shores.  This  river  has  its  source  in  the 
Mountains  of  Lebanon,  some  distance  north  of  the  Sea  of 
Chinnerth,  Tiberius,  or  the  Sea  of  Galilee,  which  empties 
into  the  River  Jordan. 

As  the  map  in  Fig.  50  shows,  this  famous,  though  small 
river,  flows  between  ranges  of  high  hills,  or  low  moun- 
tains, that  lie  on  both  its  eastern  and  western  boundaries; 
and  these  parallel  ranges  extend  down  to  the  Gulf  of 
Akaba,  which  forms  the  eastern  boundary  of  the  Sinai 
Peninsula.  The  Sea  of  Galilee,  the  valley  of  the  Jordan 
and  the  country  between  the  Dead  Sea  and  the  Gulf  of 
Akaba,  are  all,  for  the  most  part,  considerably  below  the 
level  of  the  Mediterranean  or  the  Red  Sea;  the  Sea  of 
Galilee  being  about  626  feet  and  the  Dead  Sea  1312  feet 
below  that  line. 

That  this  country  has  been  the  scene  of  great  volcanic 
[281] 


282          VOLCANOES  AND  EARTHQUAKES 


MEDITERR.  WEAN 


26 


FIG.  50.    STRIA 


SODOM  AND  GOMORRAH  283 

activities  is  evident  from  the  volcanic  rocks  found  over 
different  portions  of  its  surface.  Moreover,  the  remains  of 
several  craters  are  still  visible.  On  the  western  banks 
of  the  Jordan  numerous  dikes  and  streaks  of  basalt  occur 
in  the  limestone  that  covers  parts  of  the  region.  Besides 
there  are  thermal  springs  whose  waters  are  at  a  tempera- 
ture, according  to  Daubeny,  of  114°  F.  Then,  too,  in  the 
neighborhood  of  the  Dead  Sea,  as  well  as  in  the  neighbor- 
hood of  the  adjoining  mountain  ranges,  there  are  quan- 
tities of  sulphur  and  asphaltum  or  bitumen,  while  on 
the  Dead  Sea  asphaltum  is  found  floating  in  sufficient 
quantity  to  be  a  source  of  considerable  revenue  to  the 
boatmen  who  collect  it.  It  was  in  this  region  that 
Sodom,  Gomorrah,  and  other  cities  of  the  plain  were 
situated;  cities  so  wicked  that  God  utterly  destroyed 
them  by  volcanoes  and  earthquakes. 

Volcanic  activity  was  evidently  common  in  this  land 
of  the  Bible  during  the  times  of  the  prophets  of  Israel; 
for  in  their  poetic  writings  are  frequent  references  to  such 
phenomena — beautiful  and  majestic  similes  and  meta- 
phors derived  from  contemplation  of  live  volcanoes. 

Jeremiah  says: 

"  Behold,  I  am  against  thee,  O  devouring  mountain, 
saith  the  Lord,  which  destroy eth  all  the  earth;  and  I  will 
stretch  out  mine  hand  upon  thee,  and  roll  thee  down  from 
the  rocks,  and  will  make  thee  a  burnt l  mountain. 

"And  they  shall  not  take  of  thee  a  stone  for  a  corner, 
nor  a  stone  for  foundations;  but  thou  shalt  be  desolate 
forever,  saith  the  Lord."  (Jer.  li,  25-26.) 

So,  too,  the  prophet  Isaiah  says: 

"Oh  that  thou  wouldst  rend  the  heavens,  that  thou 
wouldst  come  down,  that  the  mountains  might  flow  down 
at  thy  presence! 

!/.  e.,  burnt  out  mountain,  extinct  volcano. 


284         VOLCANOES  AND  EARTHQUAKES 

"As  when  the  melting  fire  burneth,  the  fire  causeth 
the  water  to  boil,  to  make  thy  name  known  to  thine  ad- 
versaries, that  the  nations  may  tremble  at  thy  presence! 

"When  thou  didst  terrible  things  which  we  look  not 
for,  thou  cameth  down,  the  mountains  flowed  down  at 
thy  presence."  (Is.  Ixiv,  1-2.) 

So,  too,  the  prophet  Nahum  says: 

"The  mountains  quake  at  him,  and  the  hills  melt,  and 
the  earth  is  burned  at  his  presence,  yea,  the  world,  and 
all  that  dwell  therein. 

"  Who  can  stand  before  his  indignation?  And  who  can 
abide  in  the  fierceness  of  his  anger?  His  fury  is  poured 
down  like  fire,  and  the  rocks  are  thrown  down  by  him." 
(Nahum,  i,  5-6.) 

Let  us  now  examine  briefly  the  description  Moses  gives 
of  the  destruction  of  Sodom,  Gomorrah,  and  other  cities 
of  the  plain.  This  destruction  occurred  during  the  life 
time  of  Abraham  and  his  nephew  Lot.  The  record  says 
that  God  told  Abraham  He  intended  to  destroy  them 
because  of  their  wickedness.  Then  follows  in  the  18th 
chapter  of  Genesis  the  eloquent  pleading  of  Abraham  for 
one  of  the  doomed  cities.  At  Abraham's  earnest  plea 
God  promises  to  spare  Sodom  if  fifty  righteous  men  can 
be  found  therein.  Obtaining  this  respite,  Abraham  re- 
peatedly asks  further  mercy  for  the  city,  and  at  last  re- 
ceives the  sacred  promise  that  the  city  shall  not  be  de- 
stroyed, if  but  ten  righteous  people  can  be  found  there. 
An  evidence  of  the  great  wickedness  of  the  city  is  seen  in 
the  fact  that  not  even  ten  could  be  found.  Whereupon 
the  Lord  gives  notice  to  Lot  that  the  cities  were  doomed 
and  commands  Lot  to  leave  at  once  with  his  family. 

"Escape  for  thy  life;  look  not  behind  thee,  neither 
stay  thou  in  all  the  plain;  escape  to  the  mountain,  lest 
thou  be  consumed!" 


SODOM  AND  GOMORRAH  285 

Moses  describes  what  happened  as  follows: 

"The  sun  was  risen  upon  the  earth,  when  Lot  entered 
into  Zoar. 

"Then  the  Lord  rained  upon  Sodom  and  upon  Gomor- 
rah brimstone  and  fire  from  the  Lord  out  of  heaven; 

"And  he  overthrew  those  cities  and  all  the  plain,  and 
all  the  inhabitants  of  the  cities,  and  that  which  grew  upon 
the  ground. 

"But  his  wife  looked  back  from  behind  him,  and  she 
became  a  pillar  of  salt. 

"  And  Abraham  gat  up  early  in  the  morning  to  the  place 
where  he  stood  before  the  Lord: 

"And  he  looked  toward  Sodom  and  Gomorrah,  and 
toward  all  the  land  of  the  plain,  and  beheld,  and  lo,  the 
smoke  of  the  country  went  up  as  the  smoke  of  a  furnace." 
(Gen.  xix,  23-28). 

This  is  clearly  the  description  of  a  volcanic  eruption, 
for  throughout  the  Bible  things  are  described  as  they 
appear  to  be.  When  Moses  speaks  of  brimstone  and  fire 
being  rained  upon  Sodom  and  Gomorrah  out  of  heaven, 
he  is  describing  the  phenomenon  as  it  would  appear  to 
one  looking  at  it.  Of  course,  we  know  that  in  volcanic 
eruptions  such  things  come  to  the  earth  through  the 
crater  of  the  volcano.  The  lava  is  thrown  high  into  the 
air,  and  the  hardening,  but  still  red  hot,  ashes,  rain  down 
on  the  earth  from  the  ash  cloud  that  forms  over  the 
mountain.  But,  looked  at  from  a  distance  they  appear 
to  fall  or  be  rained  down  from  the  skies.  In  exactly  the 
same  way,  Livy,  the  Roman  historian,  tells  about  showers 
of  stones  that  fell  from  heaven  on  Mt.  Albano  near  Rome 
for  two  whole  days  during  the  second  Punic  War.  So,  too, 
even  Pliny,  who  had  some  pretensions  to  be  considered 
a  naturalist,  in  describing  the  appearance  of  Mt.  Vesuvius 
during  the  terrible  eruption  of  A.  D.  79,  when  Herculaneam 


286         VOLCANOES  AND  EARTHQUAKES 

and  Pompeii  were  destroyed,  speaks  of  the  red  hot  stones 
and  ashes  as  falling  from  above.  So,  in  reality,  they  did, 
although,  as  in  the  case  of  the  cities  of  the  plain,  the  mate- 
rials forming  the  cloud  came  from  the  crater  of  the  volcano 
below. 

As  to  brimstone  falling  from  the  sky,  this  is  by  no 
means  an  unusual  occurrence  during  many  volcanic 
eruptions,  since  sulphur  is  a  common  material,  often 
thrown  out  of  the  craters  of  some  volcanoes. 

Note  also  the  statement  that,  when  Abraham  rose 
early  in  the  morning  and  looked  toward  the  place  where 
Sodom  and  Gomorrah  stood,  he  saw  the  smoke  of  the 
country  go  up  like  the  smoke  of  a  furnace.  This  was, 
probably,  the  smoke  caused  by  the  burning  of  the  city, 
or  even  by  the  destruction  of  the  crops  in  their  fields, 
when  ignited  by  the  falling  red  hot  ashes.  It  might  also 
have  been  partly  due  to  the  burning  of  asphalt  thrown 
out  from  the  fissures  in  the  ground,  or  to  the  showers  of 
volcanic  ashes  that  fell  from  the  cloud  formed  during  the 
eruption. 

That  the  cities  there  were  destroyed  by  a  volcano  far 
in  the  past  appears  from  things  outside  of  the  Bible 
proper;  for  Strabo,  the  Greek  geographer,  refers  to  Jewish 
traditions  that  thirteen  flourishing  cities  were  swallowed 
up  by  a  volcano,  and  this  finds  fair  corroboration  in  the 
ruins  along  the  western  borders  of  the  Dead  Sea. 

A  writer  referring  to  these  eruptions  says: 

"The  eruptions  themselves  have  ceased  long  since, 
but  the  effects,  which  usually  succeed  them,  still  continue 
to  be  felt  at  intervals  in  this  country.  The  coast  in  general 
is  subject  to  earthquakes,  and  history  notes  several 
which  have  changed  the  face  of  Antioch,  Laodicea, 
Tripoli,  Berytus,  Tyre,  and  Sidon.  In  1793  there  hap- 
pened one  which  spread  the  greatest  ravages.  It  is  said 


SODOM  AND  GOMORRAH  287 

to  have  destroyed  in  the  valley  of  Balbec  upwards  of 
20,000  persons." 

Attention  has  already  been  called  to  the  fact  that  the 
valley  of  the  Jordan  occupies  a  depressed  or  sunken  region 
far  below  the  level  of  the  Mediterranean  and  the  Red 
Seas.  It  is  the  belief  of  some  geologists  that  this  depres- 
sion was  caused  by  an  earthquake  which  accompanied 
the  volcanic  eruption  that  destroyed  Sodom  and  Go- 
morrah and  the  cities  of  the  plain.  Indeed,  some  con- 
tend that  the  present  site  of  the  valley  of  the  Jordan, 
including  the  Sea  of  Tiberius  and  the  Dead  Sea,  is  a  great 
fissure  that  was  made  in  the  limestone  of  the  valley  during 
the  time  of  that  earthquake. 

It  would  appear  from  the  peculiar  geography  of  this 
section  of  country  that  the  Jordan  River  has  not  always 
emptied  into  the  Dead  Sea,  but  that  before  the  time  of 
the  destruction  of  the  Cities  of  the  Plain  the  greater  part 
of  the  country  now  occupied  by  the  Dead  Sea  was  a  fer- 
tile valley,  and  the  Jordan  emptied  directly  into  the  Red 
Sea  at  the  Gulf  of  Akaba;  that  during  the  disturbance 
through  changes  in  the  valley,  or  possibly  by  a  lava 
stream  flowing  across  a  portion  of  the  bed  of  the  lower 
Jordan,  or  even  by  a  huge  accumulation  of  stones  or  ashes 
thrown  out  from  a  neighboring  volcano,  the  discharge  of 
the  river  into  the  Red  Sea  was  cut  off,  and  that  in  this  way 
the  waters  of  the  rivers  began  to  accumulate  and  to  flow 
over  the  plain,  thus  forming  the  basin  of  the  Dead  Sea. 

There  is  no  difficulty  in  accounting  for  the  saltness  of 
the  Dead  Sea.  There  are  large  quantities  of  salt,  and 
salty  matters  generally,  in  the  volcanic  rocks  of  the  region, 
but,  even  if  this  were  not  so,  when  a  river  empties  into  a 
lake  with  no  outlet  to  the  sea,  and  which  therefore  loses 
its  water  by  evaporation  only,  the  water  will  gradually 
become  very  salt,  since  the  remaining  waters  of  such  a 


288         VOLCANOES  AND  EARTHQUAKES 

lake  contain  more  or  less  salt,  while  the  water  they  lose 
by  evaporation  contains  none. 

The  waters  of  the  Dead  Sea  are  very  salt,  but  not  the 
saltest  in  the  world.  In  every  100  pounds  of  Dead 
Sea  water  twenty-four  pounds  consist  of  salty  matters. 
The  waters  of  the  Great  Salt  Lake,  in  Utah,  contain  eight- 
een per  cent  of  salty  matters.  Lake  Van,  in  eastern 
Turkey,  is,  perhaps,  the  saltest  lake  on  earth,  it  containing 
no  less  than  thirty-three  pounds  of  salty  substances  in 
every  100  pounds  of  water. 

Daubeny,  an  authority  on  volcanoes,  and  quite  com- 
petent to  give  an  opinion  concerning  what  is  possible  in 
this  line,  describes  what  he  believes  took  place,  as  follows: 

"Briefly  then  to  recapitulate  the  train  of  phenomena 
by  which  the  destruction  of  the  cities  might  have  been 
brought  about,  I  would  suppose  that  the  River  Jordan, 
prior  to  that  event,  continued  its  course  tranquilly  through 
the  great  longitudinal  valley,  called  El  Arabah,  into  the 
Gulf  of  Akaba;  that  a  shower  of  stones  and  sand  from 
some  neighboring  volcano  first  overwhelmed  these  places; 
and  that  its  eruption  was  followed  by  a  depression  of  the 
whole  of  the  region,  from  some  point  apparently  inter- 
mediate between  the  lake  of  Tiberius  and  the  mountains  of 
Lebanon,  to  the  watershed  in  the  parallel  of  30°,  which 
occurs  in  the  valley  of  El  Arabah  above-mentioned.  I 
would  thence  infer  that  the  waters  of  the  Jordan,  pent-up 
within  the  valley  by  a  range  of  mountains  to  the  east  and 
west,  and  a  barrier  of  elevated  table-land  to  the  south, 
could  find  no  outlet,  and  consequently  by  degrees  formed 
a  lake  in  its  most  depressed  portion,  which,  however,  did 
not  occur  at  once,  and  therefore  is  not  recorded  by  Scrip- 
ture as  a  part  of  the  catastrophe,  though  reference  is 
made  in  another  passage  of  its  existence  in  what  was 
before  the  valley  of  Siddim." 


SODOM  AND  GOMORRAH  289 

As  regards  the  turning  of  Lot's  wife  into  a  pillar  of  salt, 
Henderson,  who  has  carefully  studied  this  part  of  the 
country,  remarks:  "How  natural  is  the  incrustation  of 
his  wife  on  this  hypothesis!  Remaining  in  a  lower  part  ot 
the  valley,  and  looking  with  a  wistful  eye  towards  Sodom, 
she  was  surrounded,  ere  she  was  aware,  by  the  lava,  which 
rising  and  swelling,  at  length  reached  her,  and  (whilst 
the  volcanic  effluvia  deprived  her  of  life)  incrusted  her 
where  she  stood,  so  that  being,  as  it  were,  embalmed  by 
the  salso-bituminous  mass,  she  became  a  conspicuous 
beacon  and  admonitory  example  of  future  generations." 


CHAPTER  XXXI 

INSTRUMENTS    FOR    RECORDING    AND    MEASURING    EARTH- 
QUAKE SHOCKS 

To  attempt  by  the  unaided  senses  a  determination  of 
the  direction  in  which  earthquake  shocks  reach  any  cer- 
tain spot,  the  velocity  with  which  they  are  travelling, 
their  degree  of  intensity,  their  general  character,  whether 
horizontal  or  vertical,  or  any  peculiarities  which  might 
show  them  to  be  exceptional  would  be  futile  for  more 
reasons  than  one.  Even  a  skilled  scientific  observer, 
familiar  with  what  has  already  been  discovered  and  eager 
to  discover  more,  might  in  the  excitement  of  an  earthquake 
become  so  excited  himself  as  to  make  him  unable  to  take 
reliable  observations. 

But  human  ingenuity  has  succeeded  in  devising  delicate 
instruments  capable  of  recording  not  only  the  exact  time 
of  the  arrival  of  an  earthquake  shock,  but  also  of  measur- 
ing the  different  parts  of  what  may  seem  to  be  a  single 
shock,  the  direction  in  which  the  shocks  reach  the  place, 
as  well  as  the  variations  of  intensity  in  all  the  shocks. 

Crude  instruments  to  do  some  of  these  things  have  been 
in  use  from  very  early  times.  According  to  Mallet  among 
the  more  important  of  these  early  instruments  was  the 
following:  the  instrument  of  Cacciatore  of  Palmero. 
This  consisted  of  a  circular  wooden  dish,  about  ten  inches 
in  diameter,  placed  horizontally,  and  filled  with  mercury 
to  the  brim  of  eight  notches  at  equal  distances  apart. 
Beneath  each  notch  was  placed  a  small  cup.  On  the  pas- 
[290] 


RECORDING  INSTRUMENTS  291 

sage  of  the  earthquake  waves  the  vessel,  being  tilted  in  a 
direction  dependent  on  the  direction  in  which  the  waves 
were  travelling,  would  cause  some  of  the  mercury  to  spill 
over  into  one  or  more  of  the  cups,  thus  indicating  by  its 
amount  the  intensity  of  the  wave,  and  by  the  particular 
cup  or  cups  that  were  filled,  the  direction  in  which  the 
waves  reached  the  place. 

Somewhat  similar  contrivances  were  of  a  vessel  partly 
filled  with  molasses,  or  other  sticky  liquid;  or  a  cylindrical 
tub,  the  sides  of  which  were  chalked  or  whitewashed  and 
filled  with  some  colored  liquid.  In  either  of  these  cases, 
on  the  passage  of  the  earthquake  waves,  the  vessels  were 
tilted  and  showed  by  the  height  of  the  marks  the  intensity 
of  the  waves,  and  by  the  position  of  the  marks  the  direc- 
tion in  which  the  waves  first  reached  the  instrument. 

These  instruments,  though  satisfactory  for  the  study 
of  earthquake  shocks  a  long  time  ago,  when  an  earth- 
quake was  regarded  as  practically  consisting  of  but  a 
single  shock,  or,  at  the  most,  of  a  very  few  shocks,  would 
be  worthless  for  the  study  of  earthquakes  now,  for  it  is 
finally  known  that  an  earthquake  consists  of  a  series  of 
many  hundreds  of  vibrations,  differing  greatly  in  their 
rapidity  and  intensity,  and  following  one  another  in  a 
definite  order. 

The  old  forms  of  earthquake  instruments  were  known 
as  seismoscopes.  The  word  seismoscope  is  a  compound 
word  from  Greek  consisting  of  the  two  words,  seism  and 
scope.  It  means  literally  any  instrument  capable  of 
seeing,  or  calling  attention  to,  a  seism,  or  earth-shake. 
In  other  words,  a  seismoscope  is  any  instrument  capable 
of  calling  attention  only  to  an  earth-shake. 

Of  course,  neither  of  the  rude  seismoscopes  just  men- 
tioned would  be  able  to  give  any  valuable  indications  of 
the  successive  shakings  to  which  the  vessel  containing  the 


292          VOLCANOES  AND  EARTHQUAKES 

viscid  liquid  had  been  subjected,  since  the  liquid  would 
simply  be  splashed  a  number  of  times  over  the  same  parts 
of  the  vessel.  In  order  to  get  a  record  of  the  successive 
shocks  another  form  of  apparatus  must  be  employed,  a 
form  known  as  a  seismograph. 

Concerning  the  complex  character  of  the  apparently 
single  earthquake  shock,  Professor  Milne  makes  this 
highly  interesting  and  picturesque  statement: 

"An  earthquake  disturbance  at  a  station  far  removed 
from  its  origin  shows  that  the  main  movement  has  two 
attendants,  one  which  precedes  and  the  other  which  fol- 
lows. The  first  of  these  by  its  characteristics  indicates 
what  is  to  follow,  whilst  the  latter,  in  a  very  much  more 
pronounced  manner,  will  often  repeat  at  definite  intervals, 
but  with  decreasing  intensity,  the  prominent  features  of 
what  has  passed.  Inasmuch  as  these  latter  rhythmical, 
but  decreasing,  impulses  of  the  dying  earthquake  are  more 
likely  to  result  from  reflection  than  from  interference,  I 
have  provisionally  called  them  Echoes." 

There  are  many  different  forms  of  instruments  known 
as  seismographs  that  are  capable  of  recording  all  of  these 
vibrations,  but  there  is  this  objection  to  their  use:  that 
the  records  appear  in  so  tangled  a  form  that  it  is  practi- 
cally impossible  to  decipher  or  untangle  them.  This  fact 
can  be  grasped  by  examining  Fig.  51,  which  represents  a 
record  of  this  kind. 

It  is  necessary,  therefore,  to  employ  a  modified  form  of 
instrument  called  a  seismometer,  able  not  only  to  record 
all  the  different  vibrations,  but  to  record  them  in  such  a 
manner  that  they  can  be  easily  recognized.  Fig.  52,  for 
example,  shows  results  obtained  by  the  use  of  a  seismom- 
eter, in  which  the  different  vibrations  are  separated, 
and  so  recorded  on  a  sheet  of  paper,  as  to  be  readily 
understood.  Such  a  record  is  called  a  seismogram,  and 


RECORDING  INSTRUMENTS 


293 


represents  a  long  distance  seismogram.  Here  the  large 
arrow  indicates  the  beginning  of  the  record.  And  herein, 
as  can  be  clearly  seen,  what  would  appear  to  an  observer 


s 


FIG.  51.     COMPLEX  RECORD  OF  SEISMOGRAPH 


without  an  instrument  only  a  single  shock,  lasting  but 
the  fraction  of  a  minute,  in  reality  consists  of  the  prelimi- 
nary shake  as  represented  in  ab  and  be,  the  principal 
shake,  as  represented  at  c,  dl,  d2,  and  d3,  and  the  final 


FIG.  52.    LONG  DISTANCE  SEISMOGRAM 

portions  of  the  shake  or  the  "echoes"  of  Professor  Milne, 
as  represented  from  d3  to  e. 

Except  in  a  very  general  way  there  is  for  present  pur- 
poses no  need  of  explaining  the  construction  and  opera- 
tion of  the  seismometer  and  seismograph.  Suffice  it  to 
say,  there  are  many  forms  of  these  instruments,  any  of 


294          VOLCANOES  AND  EARTHQUAKES 


which  are  capable  of  recording  the  details  of  a  passing 
shock.  The  most  important  thing  in  either  a  seismograph 
or  a  seismometer  is  to  obtain  what  is  known  as  a  steady 

point;  that  is,  a  point 
consisting  of  some 
object  or  mass  that 
will  remain  practi- 
cally at  rest,  while 
everything  around 
it,  even  the  support 
which  holds  it,  is  af- 
fected by  the  earth- 
quake. 

It  is,  of  course, 
not  very  easy  to  ob- 
tain a  steady  point, 
but  it  can  be  done; 
and  it  will  be  at  once 
comprehended  that 
if  a  plate  or  piece  of 
paper  were  attached 
to  such  a  steady 
point  or  mass,  and 
a  pencil  or  tracer 
had  one  of  its  ends 
resting  on  the  plate, 
and  its  other  end  attached  to  the  support  that  vibrates 
with  the  earth,  a  tracing  or  record  would  be  drawn  on 
the  plate  from  which  the  character  of  the  motion  of  the 
end  of  the  tracer,  and,  therefore,  of  the  earth,  would  be 
marked  on  the  plate. 

Various  devices  have  been  employed  for  the  steady 
points.  The  most  successful  consists  of  a  heavy  mass  of 
lead. 


FIG.  53.    VICENTINI  VERTICAL  PENDULUM 


RECORDING  INSTRUMENTS 


295 


Fig.  53  represents  a  form  of  instrument  invented  by 
Professor  Vicentini  of  Italy.  Here  the  steady  point  con- 
sists of  a  heavy  leaden 
bob,  of  200,  400,  or  even 
500  kilograms,  suspended 
by  three  metallic  rods 
united  above  by  a  brass 
cap,  hung  on  a  steel  wire 
to  a  bracket  fixed  on 
the  wall.  This  wire  may 
have  a  length  as  great  as 
fifty  feet. 

Fig.  54  represents  the  re- 
cording instrument.  Here 
a  tracer  is  provided  that 
is  capable  of  multiplying 
the  motion  fifty  times,  or 
even  eighty  times.  A 
record  is  traced  on  a  sheet 


FIG.  54.     VICENTINI  PENDULUM  AND  RECORDER 


roller  which  imparts  a  rapid  motion  to  a  sheet  so  as  to 
make  sure  that  the  different  parts  of  the  shock  or  vibra- 
tion will  be  recorded  on  separate  portions  of  the  paper. 


CHAPTER  XXXII 

SEAQUAKES 

As  earthquakes  are  shakings  of  the  earth's  crust  in 
places  where  it  is  uncovered  by  the  waters  of  the  ocean, 
so  seaquakes  are  the  shakings  of  those  portions  that  lie 
on  the  bed  of  the  ocean. 

Mallet  points  out  that  the  earthquake  wave  may  start 
either  in  the  interior  of  the  continent,  or  on  the  bed  of 
the  ocean;  that  the  latter  place  is  the  more  common, 
since  on  the  land  vents — rude  safety-valves,  as  it  were, — 
are  provided  by  the  craters  of  the  volcanoes;  that,  when 
earthquakes  start  on  the  ocean  bed,  the  impulses  are  con- 
veyed in  different  forms  of  waves,  i.  e.,  those  through  the 
solid  earth,  those  through  the  water,  and  those  through 
the  air,  with  varying  sounds  like  bellowings  and  explo- 
sions, or  like  the  rolling  of  wagons  over  rough  roads. 

To  learn  when  quakes  occur  on  the  sea  is  a  much  harder 
task,  since  on  the  land  we  can  use  seismoscopes,  seis- 
mographs, or  seismometers  to  indicate,  record,  or  measure 
the  shakings  of  the  crust,  while  on  the  sea,  where  the 
water  is  always  in  more  or  less  motion  and  the  surface  so 
far  from  the  ocean's  bed  this  is  impossible,  or,  rather  shall 
it  be  said,  has  hitherto  been  found  so;  for  that  the  mind  of 
man  may  surmount  this  obstacle  is  not  impossible  to 
conceive. 

To  detect  the  wave  produced  by  the  quaking  of  the  bed 
of  the  ocean  is  exceedingly  difficult,  since  those  in  very 
deep  water  are  flat  or  possess  but  a  small  height.  Indeed, 
[296] 


SEAQUAKES  297 

in  the  deepest  parts  of  the  ocean  this  height  is  probably 
to  be  measured  only  by  inches  instead  of  feet.  When, 
however,  the  waves  advance  towards  the  shore  they 
increase  in  height,  and  when  they  reach  the  shallows 
near  the  coast,  they  begin  to  curl  over  and  break,  thus 
creating  the  enormous  waves  mentioned  so  often  as 
attending  great  earthquakes  in  the  ocean. 

During  the  great  earthquake  of  Simoda  in  Japan, 
1854,  the  waters  of  the  bay  were  first  greatly  agitated, 
and  then  retreated,  leaving  the  bottom  bare  in  places 
where  the  water  was  formerly  thirty  feet  deep.  A  wave, 
thirty  feet  high,  then  rushed  in  from  the  bay  and,  climb- 
ing the  land,  swept  away  everything  in  its  path,  covering 
the  town  with  water  to  the  tops  of  the  houses.  This 
monster  wave  then  receded,  but  rushed  back  five  times. 

In  1751,  an  earthquake  wave  suddenly  entered  Callao, 
the  port  of  Lima,  Peru,  sinking  twenty-three  vessels  and 
driving  a  frigate  inland,  where  it  was  left  high  and  dry. 
This  wave  extended  across  the  Pacific  to  the  Hawaiian 
Islands,  a  distance  of  6,000  miles. 

On  the  13th  of  August,  1866,  an  earthquake  wave,  that 
started  a  short  distance  from  shore,  produced  a  number 
of  earthquake  waves  sixty  feet  high  that  reached  the 
coast  of  Peru  half  an  hour  after  the  principal  earthquake 
shock.  These  waves  reached  Coquimbo,  800  miles  dis- 
tant, in  about  three  hours,  and  Honolulu,  on  the  Sandwich 
Islands,  5,520  miles  distant,  in  twelve  hours,  and  the  coast 
of  Japan,  more  than  10,000  miles  distant,  on  the  next 
day.  Le  Conte  remarks  that  these  waves  would  have 
encircled  the  earth,  had  it  not  been  for  the  barrier  inter- 
posed by  the  Andes. 

Another  great  seaquake,  known  as  the  Iquiqui  sea- 
quake, during  1868  in  the  same  neighborhood  damaged 
severely  the  towns  of  north  Chile  and  southern  Peru. 


298          VOLCANOES  AND  EARTHQUAKES 

While,  however,  there  is  difficulty  in  readily  observing 
the  earthquake  waves  that  form  in  the  deep  ocean,  yet 
such  is  at  times  the  violence  of  an  earthquake  that  there 
is  no  difficulty  in  detecting  its  presence,  even  in  deep 
water.  Dr.  Rudolph  has  made  a  careful  study  of  the 
evidences  of  earthquakes  produced  in  the  deep  sea, 
from  a  careful  examination  of  a  great  number  of  the 
logs  of  ships.  Logs,  as  everybody  knows,  are  books  in 
which  the  captain  or  commanding  officer  makes  care- 
ful entries  of  all  important  happenings  to  the  vessel, 
conditions  of  the  weather  and  of  the  sea.  From  this 
source  Dr.  Rudolph  obtained  considerable  information 
of  much  value  concerning  these  phenomena. 

I  have  already  called  your  attention  to  portion  of  the 
Atlantic  Ocean  lying  near  the  Equator,  in  the  warmest 
part  of  the  ocean,  between  Africa  and  South  America, 
as  being  a  region  especially  liable  to  submarine  volcanic 
showers.  While,  generally  speaking,  there  is  nothing  in 
this  region  to  indicate  the  probability  of  submarine  dis- 
turbance, yet  suddenly,  if  a  vessel  happens  to  pass  directly 
over  the  point  of  origin  of  the  quake,  there  ensues  a  great 
quaking  or  quivering.  Loose  objects  on  the  ship  begin  to 
shake  and  clatter.  Noises  arise  from  some  invisible  point 
deep  down  in  the  ocean.  The  disturbance  grows,  the 
noises  begin  to  resemble  distant  thunder,  the  ship  trembles 
and  staggers  as  though  it  had  struck  rocks,  and  many 
believe  she  is  about  to  go  down;  when,  as  suddenly  as  it 
began,  the  commotion  ceases,  the  noises  stop,  and  the 
ship  shapes  her  course  as  calmly,  and  as  gallantly,  as 
before. 

Rudolph  gives  two  excellent  examples  of  seaquakes 
in  this  region,  both  of  which  were,  doubtless,  due  to  sub- 
marine eruptions. 

On  the  25th  of  January,  1859,  as  the  ship  Florence  was 


SEAQUAKES  299 

in  lat.  0°  48'  N.,  long.  29°  16' W.,  about  ten  miles  N.  W. 
by  N.  from  St.  Paul's  Rock,  the  people  on  board  felt  a 
sudden  shock  that  began  with  a  rumbling  sound  like  dis- 
tant thunder.  This  lasted  only  forty  seconds.  The  glass 
and  dishes  of  the  vessel  rattled  so  violently  that  it  was 
feared  they  would  be  broken.  The  shakings  were  so 
strong  that  several  objects  on  the  vessel  were  thrown 
down.  Everyone  believed  the  ship  had  struck  on  rocks. 
The  captain  leaned  over  the  taffrail  in  order  to  see  the 
position  of  the  reef,  but  soon  saw  that  the  vessel  had 
struck  nothing,  and  informed  his  crew  "it  was  only  an 
earthquake  shock." 

Another  of  the  log  books  examined  by  Rudloph  was 
that  of  a  ship  in  the  same  part  of  the  Atlantic  Ocean. 
This  record  showed  that  suddenly  on  a  morning,  in  1883, 
strange  noises  were  heard  that  soon  increased  and  became 
not  unlike  the  firing  of  great  guns  or  the  peals  of  distant 
thunder.  The  ship  vibrated  as  if  its  anchor  had  been 
suddenly  let  go,  and  at  the  same  time  a  feeling  came  over 
all  the  crew,  as  if  they  had  been  electrified. 

In  some  cases  the  vibrations  were  sufficiently  severe  to 
throw  heavy  objects  from  the  deck,  as  appears  in  an 
account  given  by  a  French  geologist  of  a  quake  in  the 
Mediterranean  off  the  shores  of  Asia  Minor. 

"  Our  ship  was  over  the  epicentre, "  l  he  says,  "  and  was 
so  severely  shaken  that  at  first  the  Admiral  feared  the 
complete  destruction  of  the  corvette."  He  then  makes 
the  statement  that  the  shocks  which  were  directly  up- 
wards were  so  strong  as  to  throw  heavy  objects  in  the  air; 
for  example,  a  heavy  gun  and  its  carriage.  While  it  is 
possible,  as  Dutton  remarks,  that  this  incident  of  the 
heavy  gun  and  carriage  was  grossly  exaggerated,  yet  it 

1  Epicentre.  A  point  on  the  surface  of  the  earth  vertically  above 
the  point  of  origin  of  an  earthquake,  or  the  place  where  it  starts. 


300         VOLCANOES  AND  EARTHQUAKES 

should  not  be  forgotten  that  in  the  case  of  submarine 
eruptions  such  as  that  which  resulted  in  the  production 
of  the  island  of  Sabrina,  an  immense  column  of  water, 
weighing  probably  many  times  more  than  a  gun  and  its 
carriage,  was  observed  to  be  shot  high  into  the  air. 

Where  the  seaquake  is  produced  by  a  strong  submarine 
volcanic  eruption,  there  is  a  violent  commotion  of  the 
water  itself,  so  that  a  vessel  passing  over  such  a  point 
may  be  greatly  injured,  and,  indeed,  even  destroyed. 
Such  disasters,  however,  are  fortunately  exceedingly 
rare. 

Among  other  common  effects  of  seaquakes  is  the  de- 
struction of  fish  already  mentioned  by  the  sudden  blow 
to  the  water  stunning  and  killing  them,  just  as  the  ex- 
plosion of  dynamite  or  other  high  explosives  does  in  a 
lake  or  pond. 

The  most  marked  effect,  however,  of  seaquakes  is 
the  starting  of  the  great  wave  on  the  coasts  of  continents 
and  islands. 

There  are  certain  parts  of  the  ocean  that  are  especially 
liable  to  seaquakes.  Some  of  the  more  important  of 
these,  as  shown  by  Rudolph's  researches,  are: 

The  region  already  referred  to  in  the  narrowest  parts 
of  the  Atlantic  Ocean  between  Africa  and  South  America 
almost  immediately  under  the  equator.  Here  there  are 
two  well  marked  regions.  One  is  in  lat.  1°  N.,  long.  30°  W., 
where  there  is  a  submarine  ridge,  the  tops  of  which  form 
what  are  known  as  St.  Paul's  Rock.  The  ocean  here  is 
very  deep,  the  slopes  of  the  ridge  descending  rapidly. 
It  is  on  these  slopes  that  earthquakes  are  very  apt  to  occur 
just  as  they  do  on  the  steep  slopes  of  mountain  ranges. 
The  other  region,  called  by  Rudolph  the  Equatorial  Dis- 
trict, lies  a  little  further  to  the  east  on  both  sides  of  the 
equator  in  long.  20°  W. 


SEAQUAKES  301 

It  appears  from  Rudolph's  researches  that  between 
1845  and  1893  no  less  than  thirty-seven  seaquakes  were 
reported  in  the  logs  of  ships  in  the  neighborhood  of  St. 
Paul's  Rock,  and  between  1747  and  1890,  in  the  equa- 
torial district,  there  were  forty-nine  seaquakes.  It  must 
not  be  supposed,  however,  that  these  were  all  the  quakes 
in  the  regions  during  these  times,  since,  of  course,  many 
shocks  must  have  happened  that  were  not  felt  even  by 
vessels  in  the  neighborhood  and  many  more,  when  this 
portion  of  the  ocean  was  free  from  any  craft. 

In  the  North  Atlantic  there  is  a  portion  of  the  ocean's 
bed  known  as  the  West  Indies  Deep.  Here  the  bed  is 
marked  by  great  depths  and  by  many  irregularities  and 
is,  therefore,  a  region  where  seaquakes  are  common. 

Still  another  district  is  found  in  the  North  Atlantic  in 
the  neighborhood  of  the  Azores.  This  is  the  region  in 
which  the  Lisbon  earthquake  is  believed  to  have  started. 

Another  region  where  seaquakes  are  common  is  in 
the  Pacific  along  the  coast  of  South  America  from  the 
equator  to  45°  S.  lat.  "Here,"  says  Button,  "especially 
in  the  vicinity  of  the  angle  where  the  Peruvian  and 
Chilian  coasts  meet  have  they  been  most  numerous  and 
formidable.  The  harbors  of  Pisco,  Arica,  Tacua,  Iquiqui, 
and  Pisago  have  been  repeatedly  subject  to  these  destruc- 
tive invasions." 

There  has  been  considerable  discussion  as  to  the  exact 
manner  in  which  the  earthquake  waves  are  set  up. 
Whatever  be  the  cause  or  causes,  the  action  must  be  sud- 
den, such  as  an  upheaval  of  the  bottom,  or  a  collapse  of 
a  large  section  of  the  ocean's  bed,  with  a  dropping  of  a 
vast  body  of  water.  Or,  possibly,  a  submarine  volcanic 
eruption  causes  the  water  to  lift  suddenly  under  pressure 
of  steam  generated  by  escape  of  the  lava  and  other  hot 
volcanic  products. 


302          VOLCANOES  AND  EARTHQUAKES 

Dr.  Rudolph  attributes  earthquake  waves  to  sub- 
marine volcanic  eruptions  alone.  It  would  seem,  however, 
as  if  each  one  of  the  other  things  above  referred  to 
might  at  times  be  the  direct  cause. 


CHAPTER  XXXIII 

THE  DISTRIBUTION  OF  EARTHQUAKES 

Earthquakes  may  occur  at  any  part  of  the  earth's 
surface,  at  any  time  of  the  day,  or  at  any  season  of 
the  year,  yet  they  are  more  frequent  at  certain  parts, 
certain  hours,  certain  seasons. 

Since  some  earthquakes  are  unquestionably  connected 
with  volcanic  eruptions,  a  map  or  chart  of  the  volcanoes 
of  the  earth  would  also,  to  a  certain  extent,  show  the  parts 
of  the  earth  that  are  likely  to  be  visited  by  earthquakes. 
Since,  however,  by  far  the  most  severe  earthquakes  are 
not  directly  connected  with  volcanoes,  but  are  due  to 
sudden  slips  of  faulted  strata,  a  volcanic  chart  would 
necessarily  fail  to  indicate  accurately  the  principal  earth- 
quake regions. 

In  the  preparation  of  a  map  showing  the  distribution 
of  earthquakes  over  the  earth's  surface,  Mallet  adopted 
the  plan  of  colorings  or  tintings  in  such  a  manner  that 
the  depth  of  the  colors  would  represent  not  only  the  parts 
shaken,  but  also  the  relative  number  of  times  shaken,  as 
well  as  the  intensity  of  the  shocks.  In  order  to  determine 
the  depth  of  tint  to  be  employed,  Mallet  divided  earth- 
quakes into  the  following  classes  according  to  their  in- 
tensity: 

Great  earthquakes,  or  earthquakes  of  the  first  class;  or 
those  in  which  the  area  affected  is  of  great  size,  in  which 
many  cities  have  been  overthrown,   and  many  people 
killed,  and  parts  of  the  surface  greatly  altered. 
[303] 


304         VOLCANOES  AND  EARTHQUAKES 

Intermediate  earthquakes,  or  those  in  which,  although 
the  area  affected  is  great,  yet  the  destruction  of  buildings, 
or  loss  of  life,  has  been  comparatively  small. 

Minor  earthquakes,  or  those  which,  although  capable 
of  producing  small  fissures  in  the  crust,  generally  leave 
•  but  few  or  no  traces  of  their  occurrence. 

The  greatest  distance  to  which  earthquake  waves  of 
the  first  class  extend  is  taken  by  Mallet  as  being  over  a 
diameter  of  1,080  miles;  those  of  the  second  class  over  a 
diameter  of  about  360  miles,  and  those  of  the  third  class 
over  a  diameter  of  about  120  miles. 

According  to  the  Rossi  Forel  scale  already  given, 
earthquake  shocks  are  divided  according  to  their  relative 
intensity  into  ten  separate  classes,  viz.:  I.  The  micro- 
seismic;  II.  The  extremely  feeble;  III.  The  very  feeble; 
IV.  The  feeble;  V.  The  moderately  intense;  VI.  The 
fairly  strong;  VII.  The  strong;  VIII.  The  very  strong; 
IX.  The  extremely  strong;  X.  Shocks  of  extreme  intens- 
ity. 

An  earthquake  map  prepared  according  to  Mallet's 
scale  would  show  a  greater  depth  of  color  or  tint  in  the 
neighborhood  of  the  volcanic  districts  of  the  earth  and 
especially  in  the  neighborhood  of  the  mountain  regions, 
where  tectonic  quakes  are  most  frequent.  Oceanic  areas 
would  be  left  almost  untinted,  not  because  earthquakes 
do  not  occur  on  the  bed  of  the  ocean,  but  because  of  the 
difficulty  of  observing  such  earthquakes  at  great  distances 
from  the  land.  So  far  from  earthquakes  being  absent 
on  the  bed  of  the  ocean  it  is  most  probable  that  they  are 
more  frequent  there  than  elsewhere. 

Prepared  in  this  way,  Mallet's  map  would  show  a  pre- 
ponderance of  earthquakes  along  the  borders  of  the  con- 
tinents, especially  along  the  "Great  Circle  of  Fire"  on 
the  borders  of  the  Pacific  Ocean. 


DISTRIBUTION  OF  EARTHQUAKES       305 

Button  as  well  as  some  others  assert  that  the  "Great 
Circle  of  Fire"  on  the  shores  of  the  Pacific  has  in  reality 
no  existence;  that,  instead  of  there  being  a  continuous 
region  of  volcanoes,  there  is  in  reality  nothing  more  than 
a  considerable  number  of  volcanoes  arranged  in  groups 
along  the  borders  of  this  ocean,  but  separated  by  spaces 
containing  no  marked  volcanic  activity.  We  do  not  think 
this  a  tenable  position,  since  it  is  well  known  that  volcanoes 
lie  along  great  lines  of  fissures  at  different  points  or  open- 
ings which  are  kept  open  by  subsequent  volcanic  activity, 
while  the  remaining  portions  are  closed  soon  afterwards; 
and,  moreover,  in  parts  of  these  so-called  non-volcanic 
regions,  there  are  probably  extended  regions  of  extinct 
volcanoes. 

Since  the  time  of  Mallet  many  maps  have  been  made 
to  show  the  distribution  of  earthquakes.  Among  the  best 
of  such  is  that  by  M.  de  Montessus  de  Ballore. 

Some  idea  of  the  great  amount  of  work  required  for 
the  preparation  of  Montessus'  map  may  be  formed  when 
one  learns  that  the  catalogue  of  earthquakes  collected  by 
him  for  this  purpose  included  for  the  years  1880  to  1900, 
131,292  quakes. 

De  Montessus'  earthquake  map  divides  the  grand  divi- 
sions of  the  earth  into  numerous  sub-divisions,  too  nu- 
merous, indeed,  for  even  brief  description  in  a  work  of 
this  kind.  From  the  map  he  thus  laboriously  prepared 
De  Montessus  drew  the  following  general  conclusions : 

1.  The  parts  of  the  earth  that  are  most  apt  to  be  shaken 
by  earthquakes   are   those   which   possess   the   greatest 
differences  of  relief  between  their  highlands  and  lowlands, 
and  that  in  such  regions  the  most  pronounced  earthquakes 
are  found  on  the  steepest  slopes. 

2.  Earthquakes  are  most  common  along  those  parts  of 
the  crust  that  are  thrown  up  in  huge  wrinkles,  or  moun- 

T 


306         VOLCANOES  AND  EARTHQUAKES 

tain  ranges,  whether  these  masses  be  above  the  level  of 
the  sea  or  are  covered  by  it. 
3.    Earthquakes   are   more   common   in   mountainous 


FIG.  55.     DAVISON'S  EARTHQUAKE  MAP  OF  JAPAN 


districts  than  in  plains.  But  not  all  mountains  are  char- 
acterized by  earthquakes  nor  are  all  plains  free  from  them. 
Sometimes  the  plain  at  the  base  of  the  mountain  appears 


DISTRIBUTION  OF  EARTHQUAKES       307 

to  be  especially  liable  to  shocks,  probably  by  reason  of 
slips  along  faults  at  these  points. 

The  great  mountain  ranges  of  the  world  are  generally 
characterized  by  unequal  slopes,  the  long  gentle  slope 
facing  the  interior  of  the  continents,  and  the  short,  abrupt 
slopes  being  turned  towards  the  coast.  Now,  Montessus 
points  out  that  volcanoes  are  the  most  frequent  on  the 
short,  abrupt  slopes.  In  some  cases,  however,  where  the 
long  slopes  are  the  roughest,  it  is  these  slopes  that  are 
most  frequently  shaken. 

The  beds  of  the  ocean  that  lie  along  rapidly  descending 
lines,  especially  when  they  lie  on  the  borders  of  large 
mountain  ranges,  are  especially  liable  to  earthquakes. 

Dr.  Charles  Davison  has  made  a  map  of  the  earthquakes 
of  Japan  in  which  he  had  adopted  the  plan  of  representing 
the  origin  or  centres  of  earthquakes  by  a  series  of  contour 
lines  like  those  employed  on  topographical  maps.  The 
advantage  of  this  type  of  map  over  that  employed  by 
Mallet  is  just  this:  Davison's  earthquake  map  of  Japan  in 
which  the  active  volcanoes  are  marked  by  dots,  and  the 
earthquakes  by  contour  lines  surrounding  the  points  of 
origin,  discloses  the  interesting  fact  that  here  the  positions 
of  the  volcanoes  and  the  earthquake  centres  coincide, 
since  the  mountainous  districts  where  the  active  volcanoes 
are  numerous  are  singularly  free  from  earthquakes.  This 
can  be  seen  from  an  inspection  of  Fig.  55* 


CHAPTER  XXXIV 

THE  CAUSES  OF  EARTHQUAKES 

Earthquakes  occurred  long  before  man  appeared  on 
earth.  It  is  natural,  therefore,  that  our  early  ancestors, 
experiencing  these  unwelcome  phenomena,  vaguely  en- 
deavored to  explain  their  causes.  These  early  attempts 
at  explanation  have  in  many  cases  been  of  an  exceedingly 
fanciful  character. 

The  ancient  Mongolians  and  Hindoos  declared  that 
earthquakes  are  due  to  our  earth  resting  on  a  huge  frog 
and  that  they  occur  whenever  the  frog  scratches  its 
head. 

In  Japan,  where  earthquakes  are  very  common,  the 
ignorant  people  even  at  a  much  later  day  declared  that 
there  exists  in  the  depth  of  the  sea  an  immense  fish  which, 
when  angry,  dashes  its  head  violently  against  the  coast  of 
the  island,  thus  making  the  earth  tremble.  This  is, 
doubtless,  the  biggest  fish-story  extant. 

Another  folk-lore  explanation  in  Japan  attributes  the 
cause  of  the  tremblings  of  the  earth  to  a  subterranean 
monster  whose  head  lies  in  the  north  of  the  island  of 
Hondo,  while  his  tail  lies  between  the  two  principal  cities. 
The  shaking  of  his  tail  causes  earthquakes. 

Fantastic  and  foolish  as  these  explanations  are,  it  is 
worthy  of  note  that  the  first  of  the  Japanese  explanations 
shows  no  little  observation  on  the  part  of  the  people, 
since  it  locates  the  starting-points  of  earthquakes  as  being 
not  on  the  land,  but  on  the  bottom  of  the  sea.  In  point 
[308] 


CAUSES  OF  EARTHQUAKES  309 

of  fact,  nearly  all  the  great  earthquakes  in  Japan  seem 
to  start  somewhere  between  the  coasts  of  the  islands  on 
the  sea-bottom  that  leads  down  to  a  very  deep  part  of 
the  Pacific  known  as  the  Tuscarora  Deep. 

Many  years  ago  nearly  everyone  believed  that  earth- 
quakes were  caused  solely  by  the  forces  that  produce 
volcanic  eruptions;  that  all  earthquakes,  whether  in  the 
neighborhood  of  active  volcanoes,  or  at  great  distances 
therefrom,  were  to  be  regarded  solely  as  volcanic  in  their 
origin. 

It  is  now  recognized  that  the  most  severe  and  far- 
reaching  earthquakes  have  no  immediate  connection  with 
volcanic  explosions,  but  are  due  to  the  sudden  slippings 
of  the  earth's  strata  over  lines  of  faults;  or,  in  other 
words,  earthquakes  are  most  frequently  of  the  tectonic 
type. 

At  the  present  time  there  is  unfortunately  much  differ- 
ence in  opinion  as  to  the  exact  cause  of  earthquakes. 
By  this  is  not  meant  the  immediate  cause,  but  the  ultimate 
cause.  As  to  the  immediate  cause,  practically  all  are 
agreed  that  quakes  of  volcanic  origin  are  to  be  traced  to 
the  same  forces  that  produce  volcanic  eruptions,  while 
quakes  of  tectonic  origin  are  due  directly  to  the  slipping 
of  the  strata  along  the  faults.  But  when  inquiry  is  in- 
stituted as  to  the  nature  of  the  forces  that  cause  the  vol- 
canic eruptions,  or  that  produce  such  an  alteration  of  the 
strata  as  permits  them  afterwards  to  slip  and  thus  jar 
the  earth,  there  is  much  difference  of  opinion. 

As  can  be  seen  from  a  few  quotations  of  well-known 
authorities,  only  two  kinds  of  earthquakes  exist;  namely, 
volcanic  earthquakes  and  tectonic  earthquakes. 

Dana,  for  example,  while  acknowledging  that  small 
earthquakes  may  be  caused  by  the  sudden  falling  of  large 
rock  masses  into  cavities  in  the  crust  of  the  earth,  says: 


310         VOLCANOES  AND  EARTHQUAKES 

"  But  true  earthquakes  come,  for  the  most  part  at  least, 
from  one  or  the  other  of  the  following  sources  of  disturb- 
ance. 

"1.  Vapors  suddenly  produced,  causing  ruptures  and 
friction. 

"2.  Sudden  movements  or  slips  along  old  or  new  frac- 
tures. 

"Earthquakes  due  to  the  former  of  these  methods  are 
common  about  volcanoes,  and  at  the  Hawaiian  islands 
shakings  that  are  destructive  over  the  island  of  Hawaii 
at  the  moment  of  some  of  the  more  violent  eruptions,  do 
not  often  affect  the  island  of  Oahu,  a  depth  of  500  fathoms 
of  water,  the  least  depth  between  the  two  islands,  being 
sufficient  to  stop  off  the  vibrations.  .  .  . 

"Earthquakes  of  the  second  mode  of  origin  may  occur 
in  all  regions,  volcanic  or  not.  They  have  their  origin 
mostly  in  the  vicinity  of  mountain  regions,  where  old 
fractures  most  abound.  The  vibrations  may  begin  in 
a  slip  of  a  few  inches,  in  fact;  but  where  there  has  been  a 
succession  of  slips,  up  and  up  from  10,000  feet  or  more, 
as  in  the  Appalachian,  earthquakes  of  inconceivable 
volcanic  activity  must  have  resulted." 

Dana  points  out  that  volcanoes  stand  on  lines  of  frac- 
tures in  the  openings  of  which  their  existence  began  and 
that,  during  geological  time,  slips  up  or  down  these  frac- 
tures have  occurred,  producing  earthquakes  and  possibly 
starting  eruptions. 

Prestwich,  a  well-known  English  geologist,  speaks 
very  decidedly  concerning  the  causes  of  earthquakes: 

"For  my  own  part,  I  am  disposed  to  share  the  belief 
expressed  by  Dana  that  the  tension  or  pressure,  by  which 
the  great  oscillations  or  plications  of  the  earth's  crust 
have  been  produced,  have  not  entirely  ceased;  and  that 
this  is  generally  the  most  probable  cause  of  earthquakes. 


CAUSES  OF  EARTHQUAKES  311 

The  uplifting  of  the  great  continental  tracts  and  moun- 
tain ranges  must  have  always  left  the  interior  of  the  crust 
in  a  state  of  unstable  equilibrium,  and  any  slight  slide 
or  settling  along  an  old  fracture,  or  in  highly  disturbed 
and  distorted  strata,  would  be  attended  by  an  earth- 
quake shock. 

"In  volcanic  areas  the  removal  of  the  large  volumes  of 
molten  rock  from  the  interior  to  the  surface  must  produce 
settlements  and  strains  which  might  also  result  in  some 
of  these  minor  earthquakes  to  which  volcanic  districts 
are  so  subject.  Where  we  have  the  two  conditions  com- 
bined, as  they  are  in  the  Andes  in  South  America,  these 
earthquake  phenomena  are,  as  we  should  expect,  de- 
veloped on  the  grandest  and  widest  scale. 

Geikie,  the  Scotch  geologist,  says: 

"Various  conceivable  causes  may,  at  different  times  and 
under  different  conditions,  communicate  a  shock  to  the 
subterranean  regions.  Such  as  the  sudden  flashing  into 
steam  of  water  in  the  spherodial  state,  the  sudden  con- 
densation of  steam,  the  explosion  of  a  volcanic  outpour, 
the  falling  in  of  the  roof  of  a  subterranean  cavity,  or  the 
sudden  snap  of  deep-seated  rocks  subjected  to  prolonged 
and  intense  stress." 

Sir  Charles  Lyell,  the  great  English  'geologist,  holds 
the  following  views  concerning  the  origin  of  earthquakes. 
He  speaks  as  follows  in  his  "  Principles  of  Geology": 

"1.  The  primary  cause  of  the  volcanoes  and  the  earth- 
quakes are  to  a  great  extent  the  same,  and  connected  with 
the  development  of  heat  and  chemical  action  at  various 
depths  in  the  interior  of  the  globe. 

"  2.  Volcanic  heat  has  been  supposed  by  many  to  be  the 
result  of  the  high  temperature  which  belonged  to  the  whole 
planet  when  it  was  in  a  state  of  igneous  fusion,  a  temper- 
ature which  they  suppose  to  have  been  always  diminish- 


312          VOLCANOES  AND  EARTHQUAKES 

ing  and  still  to  continue  to  diminish  by  radiation  into 
space.  .  .  . 

"The  powerful  agency  of  steam  or  aqueous  vapor  in 
volcanic  eruptions  leads  us  to  compare  its  power  of  pro- 
pelling lava  to  the  surface  with  that  which  it  exerts  in 
driving  up  water  in  the  pipe  of  an  Icelandic  geyser. 
Various  gases  also,  rendered  liquid  by  pressure  at  great 
depths,  may  aid  in  causing  volcanic  outbursts  and  in 
fissuring  and  convulsing  the  rocks  during  earthquakes." 

Major  Clarence  Edward  Button,  U.  S.  A.,  an  acknowl- 
edged authority  on  seismology,  speaks  as  follows: 

"Thus  far,  then,  we  have  two  causes  of  earthquakes 
which  are  apparently  well  sustained:  (1)  the  downthrows, 
which  have  often  been  observed  to  be  accompanied  by 
earthquakes,  and  (2)  volcanic  action.  But  neither  of 
them  have  been  shown  to  be  connected  with  more  than 
a  comparatively  small  number.  Much  the  greater  part 
of  the  earthquakes  still  require  explanation,  and  the 
indications  are  manifold  that  some  of  them  are  produced 
by  some  cause  yet  to  be  stated." 

He  acknowledges,  however,  this  unknown  cause  may 
be  traceable  to  volcanic  agency.  To  quote  him  in  full: 

"It  remains  now  to  refer  to  the  possibility  that  many 
quakes  whose  origin  is  unknown,  or  extremely  doubtful, 
may,  after  all,  be  volcanic.  This  must  be  fully  admitted, 
and,  indeed,  it  is  in  many  cases  highly  probable.  Evi- 
dences that  volcanic  action  has  taken  place  in  the  depths 
of  the  earth  without  visible,  permanent  results  on  the 
surface  abound  in  ancient  rock  exposures.  Formations 
of  great  geological  age,  once  deeply  buried  and  brought 
to  daylight  by  secular  denudations,  show  that  lavas  have 
penetrated  surrounding  rock-masses  in  many  astonishing 
ways.  Sometimes  they  have  intruded  between  strata, 
lifting  or  floating  up  the  overlying  beds  without  any 


CAUSES  OF  EARTHQUAKES  313 

indication  of  escaping  to  the  surface.  Sometimes  the  lava 
breaks  across  a  series  of  strata  and  finds  its  way  into  the 
partings  between  higher  beds.  Or  it  forces  its  way  into 
a  fissure  to  form  a  dike  which  may  never  reach  the  surface. 
In  one  place  a  long  arm  or  sheet  of  lava  has  in  a  most 
surprising  and  inexplicable  manner  thrust  itself  into  the 
enveloping  rock-mass,  and  in  the  older  or  metamorphic 
rocks  these  offshoots  or  apophyses  cross  each  other  in 
great  numbers  and  form  a  tangled  network  of  intrusive 
dikes.  In  other  places  the  intruded  lava  has  formed 
immense  lenticular  (lense  shaped)  masses  (laccolites), 
which  have  domed  up  the  overlying  strata  into  mountain 
masses.  These  intrusions,  almost  infinitely  varied  in 
form  and  condition,  are  often,  in  fact  usually,  inexplicable 
as  mechanical  problems,  but  their  reality  is  vouched  for 
by  the  evidence  of  our  senses.  What  concerns  us  here  is 
the  great  energy  which  they  suggest  and  their  adequacy 
to  generate  in  the  rocks  those  sudden,  elastic  displace- 
ments which  are  the  real  initiatory  impulses  of  an  earth- 
quake. They  assure  us  that  a  great  deal  of  volcanic 
action  has  transpired  in  past  ages  far  under  ground, 
which  makes  no  other  sign  at  the  surface  than  those 
vibrations  which  we  call  an  earthquake." 

Koto,  the  celebrated  Japanese  student  of  earthquakes, 
and  a  member  of  the  Earthquake  Investigation  Committee 
appointed  by  the  Japanese  Government  for  studying  the 
great  Mino-Owaro  earthquake,  in  Japan,  1891,  is  properly 
regarded  as  an  authority  on  earthquakes.  Living,  as  he 
does,  in  a  country  where  earthquakes  and  volcanic  erup- 
tions are  of  almost  daily  occurrence,  he  has  had  abundant 
opportunity  for  studying  these  phenomena,  especially 
in  connection  with  the  Seismological  Institute  of  Japan. 
He  speaks  as  follows: 

"To  make  clear  once  for  all  my  own  standpoint,  I 


314         VOLCANOES  AND  EARTHQUAKES 

may  say  plainly  that  the  chain  of  volcanoes  and  the  system 
of  mountains  of  the  non-volcanic  earthquake,  appear  to 
me  to  have  very  intimate  and  fundamental  relations  with 
the  so-called  tectonic  line." 

Mallet  regards  earthquakes  that  can  be  directly  trace- 
able to  volcanic  origin  as  unsuccessful  efforts  on  the  part 
of  nature  to  establish  volcanoes.  He  speaks  concerning 
this  matter  as  follows: 

"An  earthquake  in  a  non-volcanic  region  may,  in  fact, 
be  viewed  as  an  uncompleted  effort  to  establish  a  volcano. 
The  forces  of  explosion  and  impulse  are  the  same  in  both  ; 
they  differ  only  in  degree  of  energy,  or  in  the  varying 
sorts  and  degrees  of  resistance  opposed  to  them.  There  is 
more  than  a  mere  vaguely  admitted  connection  between 
them,  as  heretofore  commonly  acknowledged — one  so 
vague  that  the  earthquake  has  been  often  stated  to  be 
the  cause  of  the  volcano  (Johnson, '  Phy.  Atlas,'  Geology, 
page  21),  and  more  commonly  the  volcano  the  cause  of 
the  earthquake,  neither  view  being  the  expression  of  the 
truth  of  nature.  They  are  not  in  the  relation  to  each  other 
of  cause  and  effect,  but  are  both  unequal  manifestations 
of  a  common  force  under  different  conditions." 

Before  closing  this  chapter  on  the  causes  of  earthquakes 
it  may  be  well  to  state  briefly  the  explanations  that  have 
been  suggested  by  those  who  hold  that  the  earth  is  solid 
and  cold  throughout  its  entire  mass,  except  that  in  the 
neighborhood  of  volcanic  districts  there  are  limited 
areas  situated  only  a  comparatively  few  miles  below  the 
surface  where  the  rocks  are  highly  heated. 

Professor  Mallet  suggested  that  the  source  of  heat  for 
these  local  areas  of  melted  rocks  was  to  be  found  in  the 
enormous  mechanical  force  that  is  developed  by  the  crush- 
ing of  the  strata  in  the  earth's  crust.  The  principal  objec- 
tion to  Mallet's  theory  is  to  be  found  in  the  fact  that,  for 


CAUSES  OF  EARTHQUAKES  315 

this  heat  to  be  available  for  the  melting  of  rocks,  it  must 
be  produced  rapidly,  and  not  spread  out  over  long  periods 
of  time.  Moreover,  there  would  appear  to  be  no  other 
way  to  account  for  the  production  of  the  great  force 
required  to  effect  the  crushing  of  the  earth's  strata  save 
on  the  assumption  of  a  highly  heated  interior  still  cooling 
and  contracting. 

In  his  "Aspects  of  the  Earth"  Shaler  has  suggested  an 
hypothesis  that  may  be  regarded  to  a  certain  extent  as  ex- 
plaining how  heat,  slowly  generated,  might  be  blanketed, 
or  prevented  from  escaping  and  so  possibly  reaching  a 
temperature  sufficiently  high  to  melt  the  materials  in  por- 
tions of  the  interior  not  far  below  the  surface  of  the  earth. 

"We  thus  see  that  in  the  water  imprisoned  in  the  de- 
posits of  the  early  geological  ages  and  brought  to  a  high 
temperature  by  the  blanketing  action  of  the  more  recently 
deposited  beds,  we  have  a  sufficient  cause  for  the  great 
generation  of  steam  at  high  temperatures,  and  this  is  the 
sole  essential  phenomenon  of  volcanic  eruptions.  We  see 
also  by  this  hypothesis  why  volcanoes  do  not  occur  at 
points  remote  from  the  sea,  and  why  they  cease  to  be  in 
action  soon  after  the  sea  leaves  their  neighborhood.  .  .  . 

"The  foregoing  considerations  make  it  tolerably  clear 
that  volcanoes  are  fed  from  deposits  of  water  contained 
in  ancient  rocks  which  have  become  greatly  heated 
through  the  blanketing  effects  of  the  strata  which  have 
been  laid  down  upon  them.  The  gas  which  is  the  only 
invariable  element  of  volcanic  eruptions  is  steam;  more- 
over, it  is  the  steam  of  sea-water,  as  is  proven  by  analysis 
of  the  ejections.  It  breaks  its  way  to  the  surface  only  on 
those  parts  of  the  earth  which  are  near  to  where  the  de- 
position of  strata  is  lifting  the  temperature  of  water  con- 
tained in  rocks  by  preventing,  in  fact,  the  escape  of  the 
earth's  heat." 


316         VOLCANOES  AND  EARTHQUAKES 

Another  very  common  theory  is  that  of  chemical  action, 
or  the  heat  produced  by  the  oxidation  of  various  sub- 
stances inside  the  earth,  such,  for  example,  as  iron  pyrites, 
a  compound  of  iron  and  sulphur. 

When  Sir  Humphrey  Davy  discovered  metallic  sodium 
and  it  was  found  that  this  material,  when  thrown  on  water, 
possessed  the  power  of  liberating  intense  heat,  the  dis- 
covery was  welcomed  by  geologists  as  affording  a  possible 
explanation  of  the  cause  of  volcanoes  and  earthquakes. 

It  may  be  said  generally  concerning  chemical  action 
as  the  source  of  the  earth's  interior  heat,  that  the  chief 
objection  against  it  is  the  fact  that  such  heat  is  liberated 
too  slowly  to  result  in  the  production  of  a  very  high 
temperature.  This  objection  does  not  exist  in  the  case 
of  such  substances  as  metallic  sodium,  since  here  the 
heat  is  rapidly  developed  and  is  sufficient  in  amount  to 
fuse  the  substances  produced.  But  in  the  lava  produced 
in  such  great  quantities  as  it  is  in  volcanic  districts  there 
must  be  liberated  at  the  same  time  large  quantities  of 
gaseous  hydrogen.  Now,  although  hydrogen  is,  as  we 
have  already  seen,  sometimes  given  off  with  the  gases 
that  escape  from  volcanic  craters,  yet  the  quantity 
which  escapes  is  so  small  that  this  theory  of  volcanic 
activity  has  been  practically  abandoned. 

Quite  recently,  however,  among  the  various  chemical 
substances  that  are  produced  under  the  extremely  high 
temperatures  of  the  electric  furnace  have  been  found,  or 
formed,  a  number  of  curious  substances  such  as  calcium 
carbide,  calcium  silicide,  barium  silicide,  etc.,  that  possess 
the  property  of  becoming  highly  heated  on  coming  in 
contact  with  water. 

Now  it  is  an  interesting  fact  that  the  hydrogen  and  other 
gases  which  are  given  off  by  the  action  of  water  on  these 
substances  are  absorbed  in  large  quantities  by  the  materi- 


CAUSES  OF  EARTHQUAKES  317 

als  themselves,  so  that  the  objection  of  the  absence  of 
hydrogen  and  similar  gases  in  the  craters  of  the  volcanoes 
would  not  be  quite  as  objectionable  as  in  the  case  of  such 
substances. 

Of  course,  it  is  impossible  to  say  whether  such  sub- 
stances as  calcium  carbide,  etc.,  actually  exist  inside  the 
earth's  crust,  yet,  as  has  been  pointed  out,  the  principal 
condition  necessary  for  their  formation,  i.  e.,  a  high  tem- 
perature, existed  at  times  long  after  the  earth,  assuming 
the  correctness  of  the  nebular  hypothesis,  was  separated 
from  the  nebulous  sun. 

There  still  remains  to  be  discussed  the  most  curious 
of  all  possible  causes  that  have  been  suggested  for  the 
presence  of  the  local  heated  areas  at  comparatively  short 
distances  below  the  earth's  crust;  namely,  radio-activity. 

In  1896,  Henri  Becquerel,  a  Frenchman,  while  investi- 
gating the  power  of  the  X-rays,  when  passing  through 
certain  substances,  to  produce  phosphorescence,  or  caus- 
ing the  substances  to  shine  in  the  dark,  made  the  extraor- 
dinary discovery  that  some  of  the  salts  of  uranium 
possess  the  power  of  emitting  a  peculiar  radiation  closely 
resembling  the  X-rays,  that  is  able  to  pass  through  sub- 
stances opaque  to  ordinary  light  as  well  as  to  affect 
photographic  plates.  But  the  most  extraordinary  part 
of  this  discovery  was  that  the  salts  of  uranium  apparently 
possess  the  power  of  giving  out  this  radiation  continuously 
without  being  exposed  to  the  sun's  rays. 

This  peculiar  property  was  called  radio-activity,  and 
was  shortly  afterwards  found  to  be  present  in  many 
other  substances  besides  uranium,  and  notably  so  in  two 
newly  discovered  elements  known  as  polonium  and 
radium. 

Now  it  has  been  suggested  that  if  there  existed  some- 
where beneath  the  earth's  crust  in  these  locally  heated 


318         VOLCANOES  AND  EARTHQUAKES 

areas,  large  quantities  of  radio-active  substances,  these 
regions  would  at  last  become  highly  heated,  and  in  this 
way  likely  to  produce  volcanoes  and  earthquakes.  It 
would  not,  however,  seem  that  this  is  probably  their  true 
cause. 

From  what  has  just  been  said  it  is  clear  how  exceedingly 
difficult  it  has  become  to  explain  the  source  of  the  earth's 
interior  heat  when  the  fact  of  the  earth's  original  highly 
heated  condition  is  denied.  We  are,  therefore,  disposed 
with  Russell  to  believe,  as  stated  in  the  first  part  of  this 
volume,  that  the  ultimate  cause  of  both  volcanoes  and 
earthquakes  is  to  be  found  in  the  gradual  cooling  of  an 
originally  highly  heated  globe,  and  that  the  greater  part 
of  the  interior  is  still  in  a  highly  heated  condition,  hot 
enough  to  be  melted  but  yet  in  a  solid  condition  by  reason 
of  the  great  pressure  to  which  it  is  subjected. 


CHAPTER  XXXV 

EARTHQUAKES  OF  THE  GEOLOGICAL  PAST — CATACLYSMS 

There  were  numerous  volcanoes  in  the  geological  past; 
therefore,  since  volcanic  eruptions  are  generally  attended 
by  earthquake  shocks,  it  follows  that  during  that  remote 
past  the  earth  has  been  violently  shaken  by  earthquakes. 
Indeed,  if  we  assume,  as  we  believe  to  be  the  case, 
that  the  cause  of  earthquakes  is  correctly  to  be  traced 
to  an  originally  heated  globe  which  is  gradually  cooling, 
it  follows  that  the  earth  was  necessarily  subject  to  great 
earthquakes  almost  from  the  time  when  it  began  to 
cool. 

But  to  establish  as  a  fact  the  occurrence  of  an  earth- 
quake at  so  remote  a  time  in  the  earth's  history  is  far  more 
difficult  than  to  detect  the  occurrence  of  a  volcano  at 
that  time.  While  the  earthquake  shocks  may  produce 
fissures  in  the  earth's  crust,  and  may  be  accompanied  by 
great  changes  of  level,  yet  the  great  time  that  has  elapsed 
between  such  occurrences  and  the  present  would  permit 
the  various  geological  agencies  that  are  at  work  either 
to  cover  these  fissures  completely,  or  completely  to  re- 
move by  erosion,  or  in  other  similar  ways,  the  rocks  in 
which  they  occurred.  It  is  different  in  the  case  of  a 
volcano;  for  the  volcanic  craters  are  in  many  cases  still 
left  standing,  and  then  there  are  the  voluminous  sheets  of 
lava  that  have  spread  over  great  areas  of  the  earth,  as 
well  as  numerous  volcanic  cones.  Besides,  there  are 
thousands  of  square  miles  of  surface  that  have  been 
[319] 


320         VOLCANOES  AND  EARTHQUAKES 

covered,  often  to  great  depths,  by  deposits  of  volcanic 
dust  thrown  out  at  one  time  or  another  from  the  craters 
of  the  then  active  volcanoes. 

I  am  sure  you  will  acknowledge  that  any  force  capable 
of  causing  great  cracks  or  fissures  in  the  earth's  crust, 
must,  while  doing  this,  have  produced  violent  shakings 
of  the  earth.  Great  cracks  or  fissures  are  to  be  found  in 
the  rocks  of  all  the  geological  formations.  These  are  a 
record  of  the  earthquakes  that  must  have  attended  these 
convulsions.  And  there  is  plenty  of  evidence  to  show 
that  the  earth's  crust  has  been  torn  into  these  fissures 
in  places  deep  down  below  the  present  surface;  for,  by 
the  action  of  water,  many  of  these  portions  have  been 
uncovered  so  that  these  great  cracks  or  fissures  which 
have  been  afterwards  filled  with  a  molten  rock  that  has 
hardened  can  be  seen  in  the  great  dikes  that  still  re- 
main. 

But  there  are  still  other  evidences  of  the  existence  of 
earthquakes  during  the  geological  past.  There  are  found 
in  the  different  strata  of  the  earth's  crust  fossil  remains  of 
the  plants  and  animals  that  lived  on  the  earth  long  before 
the  creation  of  man.  By  a  careful  study  of  these  fossils 
we  know  positively  the  kinds  of  animals  and  plants  that 
lived  on  the  earth,  in  its  waters,  or  in  its  atmosphere, 
when  these  strata  were  being  deposited.  It  is  in  this  way 
possible  for  a  geologist  to  trace  the  life  of  the  earth  and 
its  development  as  it  is  written  on  the  great  book  of  which 
the  earth's  different  strata  form  the  separate  pages. 
Now,  a  careful  study  of  the  earth's  fauna  and  flora  during 
the  geological  past,  shows,  beyond  any  question,  that 
occasionally  great  changes  have  occurred  in  the  earth; 
for,  here  and  there,  during  different  times,  we  find  that 
certain  species  of  animals  and  plants  have  completely 
disappeared,  to  be  followed,  after  certain  intervals,  by 


CATACLYSMS  321 

entirely  different  species.  It  is  evident,  therefore,  that 
changes  have  occurred  that  have  made  it  impossible  for 
the  animals  and  plants  that  formerly  lived  on  the  earth 
to  exist  under  the  changed  conditions.  These  occurrences 
are  known  to  geologists  as  exterminations,  catastrophes, 
or  cataclysms.  They  are  also  sometimes  called  revolutions, 
for  they  mark  a  more  or  less  complete  wiping-out  of  the 
animals  living  at  the  time  they  occurred. 

If  you  will  try  to  think  you  will  readily  understand 
how  great  a  catastrophe  must  be,  that  would  be  able 
to  wipe  out  or  completely  destroy  an  entire  race  of 
animals. 

You  have  doubtless  read  with  astonishment  the  terrible 
catastrophe  that  accompanied  the  eruption  of  Krakatoa, 
especially  at  the  loss  of  life  and  property  caused  by  the 
great  waves  that  were  set  up  in  the  ocean,  but  far  reach- 
ing as  these  losses  were  they  have  nevertheless  affected 
but  a  limited  portion  of  the  earth.  The  plain  truth  is 
even  more  stupendous,  for  catastrophes  of  the  geological 
past  appear  to  have  been  so  far-reaching  and  powerful 
as  to  affect  the  whole  surface  of  the  earth,  and  to  have 
annihilated  entire  races  of  animals  and  plants  as  if  they 
had  never  existed. 

Geologists  are  all  practically  agreed  that  there  are  only 
two  ways  in  which  such  exterminations  of  the  earth's 
life  could  have  been  caused,  and  these  are  changes  in  the 
earth's  climate,  or  the  starting  of  waves  in  the  sea  by 
great  earthquakes.  In  the  sea;  for  it  must  be  borne  in 
mind  that  in  the  geological  past  the  greater  part  of  the 
earth's  surface  was  covered  by  water,  and  the  land  areas 
were  comparatively  small  and  low,  so  that  waves  created 
by  earthquakes  might  easily  have  overwhelmed  the  entire 
land  surface. 

Of  course,  it  is  fair  to  suppose  that  in  many  cases  these 


322         VOLCANOES  AND  EARTHQUAKES 

exterminations  may  have  been  caused  by  sudden  changes 
of  climate,  such  as  would  naturally  have  resulted  from 
any  change  in  the  direction  of  hot  ocean  currents  which 
formerly  flowed  from  the  equator  to  the  poles.  The 
appearance  of  a  fairly  large  mass  of  land  in  the  central 
parts  of  the  ocean  might  readily  have  turned  aside  the 
hot  ocean  currents  that  formerly  swept  over  the  polar 
regions,  thus  greatly  lowering  the  earth's  average  tem- 
perature in  these  regions. 

But  it  seems  probable  that  the  principal  cause  of  the 
destruction  of  life  in  the  geological  past  was  produced  by 
earthquake  waves  in  the  sea,  sweeping  over  the  continents. 
Let  us,  therefore,  examine  two  of  the  earth's  principal 
geological  revolutions  or  cataclysms;  namely,  that  which 
occurred  at  the  close  of  an  early  geological  time  known 
as  the  Palaeozoic,  and  that  which  occurred  at  the  end  of 
a  geological  time  intermediate  between  the  Palaeozoic 
time  or  the  time  of  ancient  life,  called  the  Mesozoic  time, 
and  the  Cenozoic  time,  or  the  time  immediately  preceding 
the  present  time.  These  two  revolutions  are  called  by 
Dana,  the  Post-Palaeozoic,  or  Appalachian  Revolution,  and 
the  Post-Mesozoic  Revolution.  Both  were  characterized 
by  the  making  of  great  mountain  systems,  and  were, 
therefore,  especially  liable  to  repetitions  of  tremendous 
earthquakes  that  must  have  produced  enormous  waves 
in  the  ocean. 

"Palaeozoic  time,"  says  Dana,  "closed  with  the  making 
of  one  of  the  great  mountain  ranges  of  North  America — 
the  Appalachian,  besides  ranges  in  other  lands,  and  in 
producing  one  of  the  most  universal  and  abrupt  dis- 
appearances of  life  in  geological  history.  So  great  an 
event  is  properly  styled  a  revolution." 

Towards  the  close  of  the  Palaeozoic  time  immense 
disturbances  of  the  earth's  crust  occurred  during  the 


CATACLYSMS  323 

uplifting  of  the  Appalachian  Mountain  System.  One 
may,  perhaps,  form  some  faint  idea  of  the  immensity  of 
the  forces  at  work,  from  the  fact  that  there  were  great 
faults  produced  by  the  uplifting  of  the  lands  attended 
with  displacement  amounting  to  10,000  or  20,000  feet  or 
more;  that  in  parts  of  southwestern  Virginia  there  were 
flexure  faults  100  miles  in  length. 

As  to  the  probability  of  the  extensive  exterminations 
that  have  occurred  during  these  times  being  produced 
by  earthquake  waves,  Dana  speaks  thus: 

"The  causes  of  the  extermination  are  two  ....  (1)  a 
colder  climate.  ...  (2)  earthquake  waves  produced  by 
orogenic  movements  (movements  producing  mountain 
ranges).  If  North  America  from  the  west  of  the  Carolinas 
to  the  Mississippi  Valley  can  be  shaken  in  consequence  of 
a  little  slip  along  a  fracture  in  times  of  perfect  quiet 
(the  allusion  here  to  the  Charleston  earthquake,  in  1886), 
and  ruin  mark  its  movements,  incalculable  violence  and 
great  surgings  of  the  ocean  should  have  occurred  and 
been  often  repeated  during  the  progress  of  flexures,  miles 
in  height  and  space,  and  slips  along  newly  opened  frac- 
tures that  kept  up  their  interrupted  progress  through 
thousands  of  feet  of  displacements.  .  .  . 

"Under  such  circumstances  the  devastation  of  the  sea- 
border  and  the  low-lying  land  of  the  period,  the  destruc- 
tion of  their  animals  and  plants,  would  have  been  a  sure 
result.  The  survivors  within  a  long  distance  of  the  coast- 
line would  have  been  few.  The  same  waves  would  have 
swept  over  European  land  and  seas,  and  there  found 
coadjutors  for  new  strife  in  earthquake  waves  of  European 
origin.  These  times  of  catastrophe  may  have  continued 
in  America  through  half  of  the  following  Triassic  period; 
for  fully  two  thirds  of  the  Triassic  period  are  unrepre- 
sented by  rocks  and  fossils  on  the  Atlantic  border." 


324          VOLCANOES  AND  EARTHQUAKES 

Coming  now  to  the  Post-Mesozoic  revolution  this 
period  was  marked  by  the  making  of  the  greatest  of 
the  North  American  mountain  systems. 

Dana  points  out  that  this  revolution  affected  the  summit 
region  of  the  Rocky  Mountains  over  a  broad  belt  probably 
as  long  as  the  western  side  of  the  continent. 

This  great  belt  of  mountain-making  extended  from 
the  Arctic  regions  through  North  America,  probably 
paralleled  by  like  work,  of  equal  extent,  in  South  America, 
but  on  a  more  eastern  line. 

"The  disappearance  of  species,"  says  Dana,  "at  the 
close  of  Mesozoic  time  was  one  of  the  two  most  noted  in 
all  geological  history.  Probably  not  a  tenth  part  of  the 
animal  species  of  the  world  disappeared  at  the  time,  and 
far  less  of  the  vegetable  life  and  terrestrial  Invertebrates; 
yet  the  change  was  so  comprehensive  that  no  Cretaceous 
species  of  Vertebrate  is  yet  known  to  occur  in  the  rocks 
of  the  American  Tertiary,  and  not  even  a  marine  Inver- 
tebrate." 

In  tracing  the  causes  of  these  disappearances,  Dana 
points  out  that,  perhaps,  the  principal  cause  was  a  de- 
crease in  the  temperature  of  the  ocean,  since  the  destruc- 
tions were  limited  in  large  measure  to  marine  life.  He 
regards,  however,  the  other  most  probable  cause  as  trace- 
able to  earthquake  waves;  for  the  making  of  a  great  moun- 
tain range  along  the  entire  length  of  the  continent  resulted 
in  displacements  of  the  rock  formations  along  lines  hun- 
dreds of  miles  in  length.  Such  displacements  must  have 
been  attended  by  a  succession  of  earthquakes  of  unus- 
ual violence,  causing  the  destruction  by  sudden  shocks 
beneath,  and  resulting,  directly  and  indirectly,  in  waves 
sweeping  over  the  continent.  Since  at  this  time  the 
land  was  still  low  for  the  greater  part,  the  huge  waves 
must  have  repeatedly  swept  over  the  greater  part  of  the 


CATACLYSMS  325 

land,  leaving  only  the  smaller  species  of    animals  and 
the  vegetation. 

It  is  evident,  therefore,  that  during  the  geological  past 
earthquakes  occurred  that  were  probably  vastly  greater 
than  any  that  have  occurred  on  the  earth  during  more 
recent  times. 


CHAPTER  XXXVI 

THE     KIMBERLY    DIAMOND     FIELDS    AND    THEIR    VOLCANIC 
ORIGIN 

The  elementary  substance  carbon  occurs  in  three  forms, 
i.  e.,  charcoal,  graphite,  and  the  diamond.  The  commonest 
form  of  carbon  is  to  be  found  in  charcoal,  as  well  as  in 
bituminous  coal,  anthracite  coal,  and  lignite.  Graphite, 
also  known  as  plumbago,  or  black  lead,  is  the  substance  you 
have  seen  so  often  in  the  lead  of  pencils.  The  diamond, 
as  every  one  knows,  is  the  highly  prized  precious  stone 
that  sparkles  so  brightly  in  the  light,  and  is  so  hard  that 
it  is  capable  of  scratching  almost  any  other  substance. 

Diamonds  are  found  in  various  parts  of  the  world. 
We  are  now  interested  in  them,  however,  only  as  they 
occur  in  certain  parts  of  the  world,  as  in  the  great  Kim- 
berly  diamond  fields  in  Southern  Africa. 

Dr.  Max  Bauer  in  his  book  on  precious  stones  says  that 
the  discovery  of  diamonds  in  South  Africa  was  made  by  a 
traveller  named  O'Reilly,  who,  in  1867,  saw  a  child  sitting 
in  the  house  of  a  Boer  named  Jacobs,  playing  with  a 
shining  stone.  Jacob's  farm  was  a  short  distance  south 
of  the  Orange  River  near  Hopetown.  This  stone  proved 
to  be  a  diamond  weighing  some  twenty-one  and  three- 
tenths  carats  and  was  afterwards  sold  for  $2,500.  The 
incident  led  to  the  discovery  and  consequent  development 
of  the  Kimberly  diamond  fields. 

Without  going  into  a  description  of  the  different  de- 
posits in  which  diamonds  are  found,  it  will  suffice  to  say 
[326] 


KIMBERLY  DIAMOND  FIELDS  327 

that  in  the  Kimberly  district  the  diamonds  occur  distrib- 
uted through  the  materials  that  fill  peculiar  funnel- 
shaped  depressions  called  pipes  which  extend  vertically 
downward  to  unknown  depths.  The  rock  that  fills  a  pipe 
consists  of  an  entirely  different  material  from  that  in 
which  the  pipe  occurs.  The  upper  extremity  of  the  pipe 
is  generally  slightly  elevated  above  the  general  surface 
for  a  few  yards.  The  pipes  vary  in  diameter  from  twenty 
to  750  yards,  diameters  of  from  200  to  300  yards  being 
quiet  common. 

In  1892,  the  diamond-bearing  material  found  in  the 
pipes  of  the  Kimberly  mines  had  been  excavated  verti- 
cally downwards  a  distance  of  1,261  feet,  without  any 
signs  of  its  being  exhausted. 

Now,  the  materials  which  fill  the  pipe  of  the  great 
Kimberly  mine  are  practically  the  same  in  all  the  mines 
in  the  neighborhood.  At  the  upper  part  of  the  pipe  the 
materials  show  the  action  of  weathering  by  exposure  to 
the  air.  Here  the  ground  is  of  a  yellowish  color.  Below, 
the  materials  have  a  blue  color. 

According  to  Bauer  the  diamond-bearing  material  that 
fills  the  upper  part  of  the  pipe  consists  of  a  soft,  sandy 
material  of  a  light  yellow  color,  known  to  diamond  miners 
as  yellow  ground,  or  yellow  stuff. 

In  the  case  of  the  Kimberly  mine,  the  yellow  ground 
has  a  thickness  of  about  sixty  feet.  Below  it  the  mate- 
rial has  a  blue  color  and  is  known  as  the  blue  ground. 
This  latter  material  possesses  the  character  of  a  volcanic 
tuff,  which  is  a  hardened  clay.  It  is  of  a  green  or  bluish 
green  color  and  has  the  appearance  of  dried  mud.  that 
holds  or  binds  together  numerous  irregular,  tough,  and 
sometimes  rounded  fragments  of  a  green  or  bluish  black 
serpentine. 

The  diamonds  are  found  near  the  surface  in  the  yellow 


328         VOLCANOES  AND  EARTHQUAKES 

ground,  as  well  as  downwards  through  the  blue  ground. 
It  was  at  one  time  thought  that  most  of  the  diamonds 
existed  in  the  yellow  ground,  and  that  they  would  soon 
disappear  entirely  at  short  distances  below  where  the  blue 
ground  began.  Under  this  belief  some  of  the  most  valu- 
able claims  changed  hands  at  prices  far  below  their  true 
value.  It  was  soon  found,  however,  that  large  and  valu- 
able stones  existed  in  the  blue  ground,  and,  indeed,  this 
ground  has  never  been  mined  to  a  depth  below  where 
valuable  diamonds  appear. 

The  diamonds  occur  in  very  small  quantities  spread 
through  the  yellow  and  blue  grounds.  The  following 
statement  by  Bauer  will  show  this: 

"A  striking  illustration  of  their  sparing  occurrence  is 
furnished  by  the  fact  that  in  the  richest  part  of  the  richest 
mine,  namely,  in  the  Kimberly  mine,  they  constitute 
only  one  part  in  2,000,000,  or  0.00005%  of  the  blue  ground. 
In  other  mines  the  proportion  is  still  lower,  namely,  one 
part  in  40,000,000,  a  yield  which  corresponds  to  five 
carats  per  cubic  yard  of  rock." 

Of  course,  you  will  desire  by  this  time  to  know  the 
manner  in  which  the  pipes  of  the  diamond  mines  of 
South  Africa  have  become  filled  with  the  diamond- 
bearing  rocks,  and  particularly  what  diamonds  have  to 
do  with  a  book  on  volcanoes  and  earthquakes. 

Dr.  Emil  Cohen,  who  has  made  a  study  of  these  regions, 
regards  the  pipes  as  volcanic  vents  or  chimneys,  and  that 
the  materials  filling  the  pipes  have  been  brought  up  from 
below  by  volcanic  forces.  He  says: 

"  I  consider  that  the  diamantiferous  ground  is  a  product 
of  volcanic  action,  and  was  probably  erupted  at  a  com- 
paratively low  temperature  in  the  form  of  an  ash  saturated 
with  water  and  comparable  to  the  materials  ejected  by  a 
mud  volcano.  Subsequently  new  minerals  were  formed 


KIMBERLY  DIAMOND  FIELDS  329 

in  the  mass,  consequent  on  alterations  induced  in  the 
upper  part  by  exposure  to  atmospheric  agencies,  and  in 
the  lower  by  the  presence  of  water.  Each  of  the  crater- 
like  basins,  or,  perhaps,  more  correctly,  funnels,  in  which 
alone  diamonds  are  now  found,  was  at  one  time  the  outlet 
of  an  active  volcano  which  became  filled  up,  partly  with 
the  products  of  eruption  and  partly  with  ejected  material 
which  fell  back  from  the  sides  of  the  crater  intermingled 
with  various  foreign  substances,  such  as  small  pebbles, 
or  organic  remains  of  local  origin,  all  of  which  became 
imbedded  in  the  volcanic  tuff.  The  substance  of  the  tuff 
was  probably  mainly  derived  from  deep-seated  crystalline 
rocks,  of  which  isolated  remains  are  now  to  be  found,  and 
which  are  similar  to  those  which  now  crop  out  at  the  sur- 
face, only  at  a  considerable  distance  from  the  diamond 
fields.  These  crystalline  rocks  from  which  the  diamonds 
probably  took  their  origin,  were  pulverized  and  forced 
up  into  the  pipes  by  the  action  of  volcanic  forces,  and 
imbedded  in  this  eruptive  material,  these  diamonds  either 
in  perfect  crystals  or  in  fragments  are  now  found." 

So  far  as  the  volcanic  origin  of  the  diamonds  of  the 
Kimberly  diamond  fields  is  concerned,  Cohen's  theory 
has  been  generally  accepted  with  the  following  modifica- 
tions: that  the  pipes  were  not  filled  by  a  single  volcanic 
eruption,  but  by  successive  eruptions,  and  that  in  the 
case  of  the  Kimberly  mine,  the  pipes  contain  the  results 
of  as  many  as  fifteen  successive  eruptions.  There  has, 
however,  been  another  and  more  important  modification 
proposed  to  Cohen's  theory,  which  is  far  more  probable. 
It  will  be  noticed  that  Cohen's  theory  regards  the  action 
of  the  volcanic  eruption  as  only  serving  to  bring  frag- 
ments of  a  deep-seated  mother  rock  that  contained  the 
diamonds  up  from  below  with  the  material  that  fills  the 
pipe.  Now,  Prof.  Carvill  Lewis  proposes  the  follow- 


330         VOLCANOES  AND  EARTHQUAKES 

ing  very  important  change  in  Cohen's  theory:  that  the 
blue  ground  does  not  consist  of  fragmentary  material  or 
tuff,  but  was  forced  up  from  below  in  the  pipe  in  a  molten 
mass  and  consolidated  on  cooling.  In  other  words,  the 
blue  ground  is  filled  with  an  ordinary  igneous  rock  that 
was  solidified  in  place  in  the  vent  or  pipe. 

In  the  great  Kimberly  mines  the  surface  of  the  pipe 
is  divided  into  numerous  separate  claims,  each  consist- 
ing of  a  small  square  lot.  There  are  so  many  of  these 
claims  in  the  Kimberly  mine  that  its  surface  is  honey- 
combed by  numerous  square  pits.  The  work  is  done 
largely  by  native  Kaffirs  employed  there  since  the  '70's. 
As  the  material  was  removed  from  the  pit,  the  adjoining 
claims  were  separated  from  each  other  by  high  vertical 
walls. 

At  a  later  date,  in  order  to  remove  the  material  and 
separate  the  lots,  high  staging  provided  with  ropes  and 
hauling  machinery  was  erected.  The  number  of  these 
ropes  is  now  so  great  that  the  mine  has  the  appearance  of 
a  huge  cobweb. 

A  very  extensive  series  of  investigations  has  been  made 
at  a  comparatively  recent  date  by  Prof.  Henri  Moissan 
of  France  on  various  chemical  products  that  are  obtained 
under  the  influence  of  the  high  temperatures  of  the  elec- 
tric furnace.  When  a  powerful  electric  current  is  caused  to 
pass  through  a  highly  refractory  material,  that  is  to  say, 
a  material  difficult  to  fuse,  such  as  carbon,  it  raises  it  to 
an  extremely  high  temperature.  A  still  higher  tempera- 
ture can  be  obtained  by  causing  a  powerful  current  to 
flow  between  two  carbon  rods  that  are  first  brought  into 
contact,  and  then  gradually  separated  from  each  other, 
just  as  they  are  in  the  ordinary  arc  lights  employed  for 
lighting  the  streets  of  our  cities.  In  the  latter  way  a 
temperature  that  is  estimated  as  high  as  3,500°  C.  (6,332° 


KIMBERLY  DIAMOND  FIELDS  331 

F.),  can  be  readily  obtained.  Under  these  very  high 
temperatures  some  very  curious  chemical  products  have 
been  obtained  in  electric  furnaces.  These  furnaces  con- 
sist of  small  chambers  made  of  highly  refractory  materials 
closely  surrounding  the  incandescent  carbon,  or  the  carbon 
voltaic  arc.  Among  some  of  the  most  curious  of  these 
products  are  artificially  produced  diamonds. 

Moissan,  however,  was  not  the  first  to  produce  diamonds 
artificially.  As  soon  as  Lavoisier  had  experimentally 
shown  that  the  chemical  composition  of  the  diamond  and 
carbon  are  the  same,  efforts  were  made  to  convert  char- 
coal into  diamonds,  and  Despretz,  as  early  as  1849,  by 
means  of  the  combined  influence  of  a  powerful  burning 
glass,  the  oxyhydrogen  blowpipe,  and  the  carbon  voltaic 
arc  obtained  a  very  high  temperature.  He  claims  by 
this  temperature  to  have  been  able  to  change  carbon  into 
a  few  microscopic  diamonds.  It  is  quite  possible,  in  the 
light  of  later  investigations,  that  Despretz  may  have 
been  mistaken  in  his  belief  that  he  had  actually  produced 
diamonds;  but  whether  this  be  so  or  not,  he  was  certainly 
one  of  the  pioneers  in  this  early  transformation  of  char- 
coal. 

Theoretically,  all  that  would  be  required  m  order  to 
change  the  non-crystalline  form  of  carbon  into  the  dia- 
mond, would  be  to  subject  the  carbon  to  a  temperature 
sufficiently  high  to  fuse  it  and  then  permit  it  slowly  to 
crystallize.  Could  this  be  done,  there  should  be  no  trouble 
in  transforming  any  amount  of  coal  into  any  equal  amount 
of  diamonds.  But  the  transformation  is  by  no  means  as 
simple  as  might  be  supposed.  It  is  not  that  the  tempera- 
ture of  the  carbon  cannot  be  raised  to  its  point  of  fusion, 
but  that  as  soon  as  a  certain  temperature  has  been  reached, 
the  carbon,  instead  of  fusing  or  melting,  is  suddenly 
volatilized  or  turned  into  vapor.  There  is  no  doubt  that 


332         VOLCANOES  AND  EARTHQUAKES 

this  is  done.  Thousands  of  feet  of  carbon  rods  are  vola- 
tilized every  night  in  the  arc  lamps  of  our  cities,  but  the 
trouble  is  that  this  carbon  vapor  so  formed,  when  cooled, 
or  condensed,  is  not  converted  into  the  exceedingly  hard, 
clear,  crystalline  diamond,  but  into  the  soft,  dull  black 
graphite  or  plumbago. 

Now  the  process  adopted  by  Moissan  in  order  to 
cause  volatilized  carbon,  or  carbon  vapor,  to  condense 
in  the  form  of  crystalline  diamonds  was  practically  as 
follows:  he  placed  pieces  of  pure  carbon  inside  a  very 
strong  steel  tube,  such,  for  example,  as  would  be  formed 
by  boring  a  short  cylindrical  hole  in  a  piece  of  strong 
thick  steel,  and  placing  a  small  quantity  of  carbon  in- 
side the  tube  so  formed.  Closing  the  open  end  of  the 
tube  by  means  of  a  tightly  fitting  screw  plug,  he  volati- 
lized the  carbon  inside  the  tube.  The  steel,  tube,  and 
plug  formed  an  electric  furnace,  for,  as  soon  as  he  passed 
an  electric  current  through  it,  the  temperature  at  once 
became  high  enough  to  volatilize  the  carbon. 

Under  these  circumstances  the  carbon  vapor  was  sub- 
jected to  great  pressure  owing  to  the  limited  space  in 
which  it  was  liberated.  As  soon  as  this  mass  of  dense 
vapor  had  been  formed,  he  seized  the  steel  tube  with  a  pair 
of  furnace  tongs,  and  plunged  it  below  the  surface  of  cold 
water  in  a  bucket. 

Of  course,  as  the  hot  tube  suddenly  chilled,  there  was  a 
great  shrinking  in  the  walls  of  the  furnace,  so  that  the 
already  compressed  carbon  vapor  was  subjected  to  a  still 
greater  pressure  which  possibly  liquified  it.  Of  that, 
however,  we  cannot  speak  definitely.  This,  however,  can 
safely  be  asserted,  that  when  the  tube  was  broken  open 
a  confused  mass  of  small  crystals  was  found  inside,  some 
of  which,  on  examination  with  the  microscope,  were  found 
to  consist  of  small  crystals  of  two  forms  of  diamonds, 


KIMBERLY  DIAMOND  FIELDS  333 

namely,  the  black  diamond,  or  carbonado,  and  the  regular 
crystallized  diamond. 

Moissan  made  a  great  number  of  experiments  for  pro- 
ducing diamonds  in  this  way,  and  succeeded  in  forming 
some  very  beautiful,  though  microscopic,  diamonds. 

What  may  be  said  to  characterize  especially  Moissan's 
experiments  was  the  comparatively  great  number  of  dia- 
monds, so  small  as  to  be  scarcely  distinguishable  under  the 
microscope.  The  high  temperature  to  which  the  materials 
inside  the  tube  were  exposed  resulted  in  the  production 
of  numerous  minute  crystals  of  different  minerals.  In 
order  to  get  rid  of  as  many  of  these  as  possible  Moissan 
adopted  the  plan  of  subjecting  the  material  to  the  action 
of  powerful  solvents,  such  as  sulphuric  acid,  aqua  regia, 
or  a  mixture  of  sulphuric  and  nitric  acid,  and  hydro- 
fluoric acid.  These  acids  destroyed  most  of  the  minute 
crystals  of  other  minerals,  but  left  the  minute  crystals 
of  diamonds  unaffected. 

Now  it  will  be  observed  that  the  theory  proposed  by 
Prof.  Carvill  Lewis  as  to  the  probable  origin  of  the  dia- 
monds of  the  Kimberly  mines  bears  a  wonderfully  close 
resemblance  to  the  method  adopted  by  Moissan  for  the 
production  of  artificial  diamonds,  since  it  supposes  the 
diamonds  to  have  been  formed  by  the  sudden  cooling  or 
chilling  within  the  pipe  of  various  molten  materials 
brought  up  from  great  depths  by  the  volcanic  forces. 
If  this  be  true,  then  besides  the  comparatively  large  crys- 
tallized and  perfect  diamonds  found  in  the  blue  ground  of 
the  Kimberly  mines,  there  should  also  be  found  large 
quantities  of  microscopic  diamonds,  just  as  are  found  in 
Moissan's  electric  furnaces,  in  which  he  produced  artificial 
diamonds. 

Moissan,  considering  this,  obtained  a  specimen  of  the 
blue  ground  from  the  Kimberly  diamond  pipe  and  on 


334         VOLCANOES  AND  EARTHQUAKES 

subjecting  it  to  the  action  of  the  different  solvents  before 
named,  found  in  the  mass  that  was  left  undissolved  a 
great  number  of  microscopic  diamonds.  It  would  seem, 
therefore,  that  there  is  no  reasonable  doubt  but  that  the 
Kimberly  diamond  fields  had  their  diamonds  produced 
by  the  sudden  chilling  in  the  volcanic  pipes  of  molten 
materials  brought  from  great  depths  by  the  force  of  vol- 
canic eruption. 


CHAPTER  XXXVII 

THE  FABLED  CONTINENT  OF  ATLANTIS 

Besides  the  sudden  changes  of  level  that  frequently 
occur  during  earthquake  shocks  there  are  gradual  changes 
of  level  that  take  place  very  slowly  throughout  long 
periods  of  time. 

These  are  believed  to  be  due  to  the  warpings  produced 
by  the  cooling  of  an  originally  highly  heated  globe. 

It  is  not  true,  therefore,  that  the  earth's  surface  is 
fixed,  or  that  its  land  and  water  areas  remain  always  the 
same.  On  the  contrary,  what  is  land  at  one  time  is 
water  at  another  time,  and  so,  too,  water  areas  may 
become  changed  into  land  areas. 

For  the  most  part  these  changes  go  on  so  slowly  as  not 
to  be  noticeable  in  an  ordinary  lifetime.  Indeed,  in  some 
cases,  they  are  so  extremely  gradual  that  Methuselah 
himself  might  have  gone  to  his  grave  in  ignorance  of  their 
progress. 

Let  us  briefly  note  a  few  well-known  gradual  changes 
of  level. 

One  of  the  most  extensive  of  these  is  the  sinking  of  an 
immense  area,  over  6,000  miles  in  diameter,  that  covers 
a  large  part  of  the  bed  or  floor  of  the  Pacific  Ocean. 

It  is  an  easy  matter  to  observe  the  gradual  changes  of 
level  on  the  coasts,  since  the  old  water  line  can  be  at  once 
found,  but  it  is  very  difficult  to  detect  such  changes  in 
the  bed  of  the  ocean,  hidden  as  it  is  by  a  covering  of  water. 
Yet  many  things  that  seem  impossible  to  the  uninitiated 
[335] 


336         VOLCANOES  AND  EARTHQUAKES 

are  readily  solved  by  those  familiar  with  physical  science. 
Little  signs,  meaningless  to  others,  are  easily  read,  and 
these  prove  beyond  doubt  the  gradual  sinking  of  the 
ocean's  bed. 

It  was  once  believed  that  the  coral  polyps  or  animal- 
cule from  the  hard,  bony  skeletons  of  which  coral  reefs 
are  formed,  could  live  at  the  greatest  depths  of  the  ocean. 
These  minute  animals  were,  therefore,  generally  credited 
with  filling  up  the  deep  ocean,  in  certain  places,  and 
converting  it  into  dry  land,  and  poetic  philosophers  were 
pleased  to  point  to  their  indefatigable  labors  as  an  object 
lesson  to  the  slothful. 

But  these  charming,  though  fallacious,  ideas  were 
rudely  overthrown  by  the  sounding  line  and  the  drag- 
net. It  had  long  been  known  that  pieces  of  coral  rock 
were  brought  up  by  dredging  apparatus  from  the  bottom 
of  the  ocean  at  all  depths,  but  it  was  eventually  shown 
that  such  pieces  of  coral  rock  never  contained  living 
animalcule,  when  brought  from  water  at  greater  depths 
than  from  100  to  120  feet. 

It  puzzled  scientific  men  no  little  at  first  to  explain  this 
apparent  inconsistency.  If  the  coral  polyp  could  not  live 
in  water  at  greater  depths  than  from  100  to  120  feet,  how 
could  the  presence  of  coral  rock  at  a  depth  of  thousands 
of  feet  be  explained?  Happily,  however,  this  problem 
was  solved  by  the  great  naturalist,  Charles  Darwin,  who 
showed  that  coral  islands  can  only  be  formed  in  parts  of 
the  ocean  whose  beds  are  sinking  at  the  same  gradual  rate 
at  which  the  coral  rock  is  being  deposited.  The  presence, 
therefore,  of  coral  islands  on  the  bed  of  the  Pacific,  as  well 
as  along  parts  of  its  coasts,  are,  to  scientific  men,  as  good 
indications  of  its  gradual  sinking  as  if  such  facts  had  been 
written  in  the  clearest  language. 

But  there  are  other  instances  of  gradual  changes  of 


FABLED  CONTINENT  OF  ATLANTIS        337 

level  besides  the  bed  of  the  Pacific.  About  600  miles 
along  the  coast  of  Greenland,  from  Disco  Bay,  near  lat. 
69°  N.,  south  to  the  Firth  of  Igaliko,  lat.  60°  43'  N.,  the 
bed  of  the  ocean  has  been  slowly  sinking  through  400 
years.  Old  buildings  and  islands  have  been  covered  by 
the  waters,  so  that  fishermen  have  been  compelled  to  pro- 
vide new  poles  for  their  boats.  As  Sir  Charles  Lyell 
remarks : 

"  In  one  place  the  Moravian  settlers  have  been  obliged 
more  than  once  to  move  inland  the  poles  upon  which 
their  large  boats  are  set,  and  the  old  poles  still  remain 
beneath  the  water  as  silent  witnesses  of  the  change." 

Besides  these  gradual  changes  of  level  there  are  many 
others,  but  only  one  more  need  be  cited:  the  gradual 
movements  of  the  coasts  of  North  America  between 
Labrador  and  New  Jersey  that  are  rising  in  some  places, 
and  sinking  in  other  places. 

The  evidences  of  these  gradual  changes  of  level  are 
sometimes  of  such  a  character  that  he  who  runs  may  read 
them.  One  of  the  most  interesting  is,  perhaps,  that  of 
the  old  Roman  temple  of  Jupiter  Serapis,  at  Pozzuli,  on 
the  borders  of  the  Mediterranean.  This  temple,  when 
completed,  was  124  feet  in  length  and  115  feet  in  width. 
Its  roof  was  supported  by  forty-six  columns,  each  forty- 
two  feet  in  height,  and  five  feet  in  diameter.  Only  three 
of  these  columns  are  now  standing.  They  give,  however, 
unquestionable  evidence  of  having  been  submerged  for 
about  half  their  height.  Nor,  indeed,  is  the  evidence 
wanting  that  this  submergence  continued  a  considerable 
time;  for,  while  the  lower  twelve  feet  of  the  columns  re- 
main smooth  and  unaffected,  yet,  for  a  distance  of  nine 
feet  above  this  portion,  they  have  been  perforated  by 
various  stone-boring  mollusks  of  a  species  still  living  in 
the  Mediterranean.  This  witnesses  that  the  columns, 


338         VOLCANOES  AND  EARTHQUAKES 

when  submerged,  were  buried  in  mud  for  twelve  feet,  and 
surrounded  by  water  nine  feet  deep.  According  to  Dana, 
the  pavement  of  the  temple  is  still  under  water.  The 
fact  that  another  pavement  exists  below  it  shows  that 
these  changes  of  level  had  occurred  before  the  temple 
was  deserted  by  the  Romans.  It  appears,  that,  prior  to 
1845,  a  gradual  sinking  of  this  part  of  the  coast  had  been 
going  on,  but  that  since  then  there  has  ensued  a  gradual 
rising. 

The  evidences  of  these  gradual  changes  of  level  in  the 
land  and  water  surfaces  of  the  earth  cannot  be  doubted 
by  even  the  most  skeptical.  Again  and  again  has  the  dry 
land  disappeared  below  the  surface  of  the  waters  of  the 
ocean.  Again  and  again,  the  ocean's  bed  has  been  raised 
to  the  surface  and  been  converted  into  dry  land.  Suppose 
we  attempt  to  follow  one  of  the  latter  movements. 

We  will  imagine  an  extensive  area  to  have  slowly  ap- 
peared above  the  ocean.  In  due  process  of  time  this  land 
surface,  which  we  will  assume  to  have  continental  dimen- 
sions, gradually  becomes  covered  with  plant  and  animal 
life.  If  it  remains  above  the  water  for  a  sufficient  length 
of  time,  its  simple  plants  and  animals  acquire  more  and 
more  complex  forms,  so  as  to  make  it  difficult  to  detect 
any  traces  of  the  original  species  from  which  they  have 
descended,  or,  more  correctly,  ascended.  Moreover,  where 
favorable  conditions  exist,  the  continent  becomes  peopled 
with  men,  who  gradually  advance  from  barbarism  to  semi- 
barbarism  and  eventually  become  a  most  highly  civilized 
nation,  sending  to  different  parts  of  the  world  colonies, 
who  carry  with  them  the  language  and  religious  customs 
of  the  land  of  their  birth. 

But,  a  sudden  or  paroxysmal  change  of  level  occurs. 
The  highly  developed  and  densely  populated  region  is 
suddenly  swept  out  of  existence  and  completely  covered 


FABLED  CONTINENT  OF  ATLANTIS       339 

by  the  waters  of  the  ocean  until,  in  a  few  thousand  years, 
all  traces  of  its  existence  have  so  completely  disappeared 
that  but  few,  if  any,  can  be  found  willing  to  acknowledge 
it  ever  had  an  existence. 

Such,  it  is  claimed,  was  the  fate  of  the  fabled  Conti- 
nent of  Atlantis.  It  will,  therefore,  be  interesting  to 
endeavor  briefly  to  review  its  past  history  and  to  read 
some  of  the  things  that  have  been  written  about  this  part 
of  the  world,  which  appears  in  the  opinion  of  some  of 
the  ancients  to  have  actually  existed. 

References  to  Atlantis  have  been  made  by  various  early 
writers.  Solon,  the  great  Athenian  lawgiver,  who  flour- 
ished 600  years  B.  c.,  began  a  description  of  this  place  in 
verse.  This  description  was  never  completed.  At  a  later 
date  one  of  Solon's  descendants,  Plato,  who  lived  about 
400  B.  c.,  prepared  a  description  of  Atlantis,  giving  in 
detail  its  location,  the  general  character  of  its  surface,  a 
description  of  its  principal  city,  and  the  civilization  of  its 
inhabitants,  as  well  as  a  brief  reference  to  its  sudden 
destruction.  In  another  place  this  record  of  Plato  will 
be  given  in  full.  It  will  suffice  now  to  quote  briefly  what 
he  says  concerning  its  location. 

"There  was  an  island  situated  in  front  of  the  straits 
which  you  call  the  Columns  of  Heracles  (Straits  of  Gib- 
raltar). The  island  was  larger  than  Libya  and  Asia  put 
together,  and  was  the  way  to  other  islands,  and  from  the 
island  you  might  pass  through  the  whole  in  the  opposite 
continent,  for  this  sea  which  is  within  the  Straits  of  Hera- 
cles is  only  a  harbor,  having  a  narrow  entrance,  but  that 
other  is  the  real  sea,  and  the  surrounding  land  may  most 
truly  be  called  a  continent.  Now,  in  the  island  of  Atlantis, 
there  was  a  great  and  wonderful  empire,  which  had  ruled 
over  the  whole  island  and  several  others,  as  well  as  over 
part  of  the  continents;  and,  besides  these,  they  subjected 


340         VOLCANOES  AND  EARTHQUAKES 

the  parts  of  Libya  within  the  Columns  of  Heracles  as  far 
as  Egypt,  and  of  Europe  as  far  as  Tyrrhenia.  The  vast 
power,  thus  gathered  into  one,  endeavored  to  subdue  at 
one  blow  our  country  and  yours,  and  the  whole  of  the  land 
which  was  within  the  straits,  and  then,  Solon,  your  coun- 
try shone  forth,  in  the  excellence  of  her  virtues  and 
strength,  among  all  mankind,  for  she  was  the  first  in 
courage  and  military  skill,  and  was  the  leader  of  the  Hel- 
lenes. And  when  the  rest  fell  off  from  her,  being  com- 
pelled to  stand  alone,  after  having  undergone  the  very 
extremity  of  danger,  she  defeated  and  triumphed  over 
the  invaders,  and  preserved  from  slavery  those  who  were 
not  yet  subjected,  and  freely  liberated  all  the  others  who 
dwelt  within  the  limits  of  Heracles. 

"But  afterwards,  there  occurred  violent  earthquakes 
and  floods,  and  in  a  single  day  and  night  of  rain,  all  your 
warlike  men  in  a  body  sunk  into  the  earth,  and  the  island 
of  Atlantis  in  a  like  manner  disappeared,  and  was  sunk 
beneath  the  sea.  And  that  is  the  reason  why  the  sea  in 
those  parts  is  impassable  and  impenetrable,  because  there 
is  such  a  quantity  of  shallow  mud  in  the  way;  and  this  was 
caused  by  the  subsidence  of  the  island."  ("  Plato's  Dia- 
logues," ii,  517,  Timaeus). 

But  besides  Solon  and  Plato  there  are  other  ancient 
writers  who  refer  to  the  lost  island  of  Atlantis. 

^Elian,  in  his  "  Varia  Historia,"  lib.  iii,  chap,  xvii,  states 
that  Theopompos,  who  flourished  400  B.  c.,  refers  to  an 
interview  between  Midas,  King  of  Phrygia,  and  Sielus, 
in  which  the  latter  speaks  of  a  great  continent  larger  than 
Asia,  Europe,  and  Libya  together  that  existed  in  the 
Atlantic. 

Proclus  quotes  a  statement  from  an  ancient  writer, 
who  speaks  about  the  islands  of  the  sea  beyond  the  Pillars 
of  Hercules  (Straits  of  Gibraltar). 


FABLED  CONTINENT  OF  ATLANTIS      341 

Marcellus,  in  a  book  on  the  Ethiopians,  refers  to  seven 
islands  in  the  Atlantic  whose  inhabitants  preserve  legends 
of  a  greater  island  (possibly  Atlantis),  that  had  dominion 
over  the  small  islands. 

Diodorus  Siculus  asserts  that  the  Phoenicians  discovered 
a  large  island  in  the  Atlantic  beyond  the  Pillars  of  Her- 
cules several  days'  sail  from  the  coast  of  Africa. 

Homer,  Plutarch,  and  other  ancient  writers,  refer  to 
several  islands  in  the  Atlantic  situated  several  thousand 
stadia  from  the  Pillars  of  Hercules.  (A  stadium  was  a 
Greek  measure  of  length  equal  to  600  feet.  It  was  equal 
to  one-eight  of  a  Roman  mile,  or  625  Roman  feet.) 

Ignatius  Donnelly,  in  his  book,  called  "Atlantis,  the 
Ante-Diluvian  World,"  claims  that  Plato's  description  of 
Atlantis  which  has  generally  been  regarded  as  imaginary, 
was,  on  the  contrary,  historic;  that  the  prehistoric  con- 
tinent of  Atlantis  was  the  cradle  of  the  human  race;  that 
here  man  reached  his  highest  civilization;  that  Atlantis 
was  the  site  of  the  Garden  of  Eden,  the  Gardens  of  the 
Hesperides,  the  Elysian  Fields,  as  well  as  Olympus;  that, 
under  the  forms  of  the  gods  and  goddesses  of  the  ancient 
Greeks,  the  Phoenicians,  the  Hindoos,  and  the  Scandi- 
navians, are  related  the  stories  of  the  kings,  queens,  and 
heroes  of  Atlantis. 

Much  that  has  been  claimed  for  the  lost  continent  can 
hardly  be  regarded  in  any  other  light  save  that  of  imagi- 
nation. For  example,  it  has  been  asserted  that  it  was  from 
Atlantis  that  the  colonies  were  sent  out  that  peopled  the 
coast  countries  of  the  Gulf  of  Mexico,  of  parts  of  the 
valley  of  the  Mississippi,  the  basin  of  the  Amazon,  the 
western  coasts  of  South  America,  parts  of  Europe,  the 
shore  lands  of  the  Mediterranean  Sea,  the  coasts  of  Europe, 
including  the  Caspian  and  the  Black  Seas,  and  even  of 
parts  of  Africa. 


342          VOLCANOES  AND  EARTHQUAKES 

It  has  also  been  asserted  that  this  mighty  nation  of 
Atlantis  carried  the  worship  of  the  sun  to  Egypt,  which 
was  one  of  its  first  colonies,  and,  therefore,  the  civilization 
of  Egypt  was  but  an  offshoot  of  prehistoric  Atlantis. 

But  it  will  be  reasonably  objected  that,  if  such  a  mass 
of  land  ever  existed  in  the  North  Atlantic,  some  evidences 
should  still  be  found  on  the  bed  of  the  ocean.  Even 
though  great  periods  of  time  have  elapsed  since  the  dis- 
appearance of  Atlantis,  some  traces  of  its  former  existence 
should  still  remain  on  the  floor  of  the  ocean.  Are  there 
any  evidences  of  an  old  land  mass  on  this  part  of  the  floor 
of  the  Atlantic?  The  answer  is  unmistakable. 

Deep-sea  soundings  show  beyond  question  that  there 
still  exists  in  the  North  Atlantic  in  the  region  where  At- 
lantis is  said  to  have  been  located  a  submarine  island,  the 
summits  of  which  appear  above  the  waters  in  the  Azores 
and  the  Canary  Islands.  This  submarine  island  has  been 
traced  southwest  over  the  bed  of  the  ocean  for  a  distance 
of  several  thousand  miles  with  a  breadth  of  fully  1,000 
miles.  Toward  the  south  there  is  connected  with  it  an- 
other submarine  island,  the  summits  of  which  reach  above 
the  surface  in  the  islands  of  Ascension,  St.  Helena,  and 
Tristan  d'Acunha. 

But  the  testimony  of  the  submarine  islands  extends 
further  than  this.  According  to  a  number  of  careful 
soundings  it  appears  that  the  bed  of  these  parts  of  the 
ocean,  instead  of  being  characterized  by  a  comparatively 
level  surface  due  to  the  gradual  accumulation  of  silt, 
possesses,  to  a  great  extent,  the  peculiarly  sculptured 
surfaces  which  are  only  produced  by  exposure  for  a  long 
time  to  the  atmosphere. 

Other  facts  might  be  adduced  to  show  that  some  time 
during  the  first  appearance  of  man  on  the  earth  there  was 
a  large  land  mass  connecting  the  Eastern  and  Western 


FABLED  CONTINENT  OF  ATLANTIS       343 

Continents.  These  facts  include  the  wonderful  resem- 
blances existing  between  the  plants  and  animals  of  the 
Eastern  and  Western  Continents,  the  close  resemblances 
of  the  myths  and  legends  of  the  races  of  the  Eastern  and 
Western  Continents,  as  well  as  the  identity  of  their  re- 
ligious ideas,  and  the  close  similarity  of  their  language 
so  far  as  relates  to  certain  fundamental  ideas.  These 
facts  all  point  unquestionably  to  the  existence  of  some 
large  land  mass  between  the  two  continents,  and  to  this 
extent  to  throw  light  on  the  probable  existence  of  prehis- 
toric Atlantis. 


CHAPTER  XXXVIII 
PLATO'S  ACCOUNT  OP  ATLANTIS 

The  following  is  a  translation  of  Plato's  record  in  full: 

Critias.  Then  listen,  Socrates,  to  a  strange  tale,  which 
is,  however,  certainly  true,  as  Solon,  who  was  the  wisest 
of  the  seven  sages,  declared.  He  was  a  relative  and  great 
friend  of  my  great-grandfather,  Dropidas,  as  he  himself 
says  in  several  of  his  poems,  and  Dropidas  told  Critias, 
my  grandfather,  who  remembered,  and  told  us,  that  there 
were  of  old  great  and  marvellous  actions  of  the  Athenians, 
which  have  passed  into  oblivion  through  time  and  the 
destruction  of  the  human  race — and  one  in  particular, 
which  was  the  greatest  of  them  all,  the  recital  of  which 
will  be  a  suitable  testimony  of  our  gratitude  to  you.  .  .  . 

Socrates.  Very  good;  and  what  is  this  ancient  famous 
action  of  which  Critias  spoke,  not  as  a  mere  legend,  but 
as  a  veritable  action  of  the  Athenian  State,  which  Solon 
recounted? 

Critias.  I  will  tell  an  old-world  story  which  I  heard 
from  an  aged  man;  for  Critias  was,  as  he  said,  at  that  time 
nearly  ninety-years  of  age,  and  I  was  about  ten  years  of 
age.  Now  the  day  was  that  day  of  the  Apaturia  which  is 
called  the  registration  of  youth;  at  which,  according  to 
custom,  our  parents  gave  prizes  for  recitations,  and  the 
poems  of  several  poets  were  recited  by  us  boys,  and  many 
of  us  sung  the  poems  of  Solon,  which  were  new  at  the  time. 
One  of  our  tribe,  either  because  this  was  his  real  opinion, 
or  because  he  thought  that  he  would  please  Critias,  said 
[344] 


PLATO'S  ACCOUNT  OF  ATLANTIS          345 

that,  in  his  judgment,  Solon  was  not  only  the  wisest  of 
men  but  the  noblest  of  poets.  The  old  man,  I  well  re- 
member, brightened  up  at  this,  and  said  smiling:  "Yes, 
Amynander,  if  Solon  had  only,  like  other  poets,  made 
poetry  the  business  of  his  life,  and  had  completed  the  tale 
which  he  brought  with  him  from  Egypt,  and  had  not  been 
compelled,  by  reason  of  the  factions  and  troubles  which 
he  found  stirring  in  this  country  when  he  came  home,  to 
attend  to  other  matters,  in  my  opinion,  he  would  have 
been  as  famous  as  Homer,  or  Hesiod,  or  any  poet." 

"And  what  was  that  poem  about,  Critias?"  said  the 
person  who  addressed  him. 

"About  the  greatest  action  which  the  Athenians  ever 
did,  and  which  ought  to  have  been  most  famous,  but 
which,  through  the  lapse  of  time  and  the  destruction  of 
the  actors,  has  not  come  down  to  us." 

"Tell  us,"  said  the  other,  "the  whole  story,  and  how 
and  from  whom  Solon  heard  this  veritable  tradition." 

He  replied:  "At  the  head  of  the  Egyptian  Delta,  where 
the  river  Nile  divides,  there  is  a  certain  district  which  is 
called  the  district  of  Sais,  and  the  great  city  of  the  district 
is  also  called  Sais,  and  is  the  city  from  which  Amasis  the 
king  was  sprung.  And  the  citizens  have  a  deity  who  is 
their  foundress:  she  is  called  in  the  Egyptian  tongue 
Neith,  which  is  asserted  by  them  to  be  the  same  whom 
the  Hellenes  called  Athene.  Now,  the  citizens  of  this  city 
are  great  lovers  of  the  Athenians,  and  say  that  they  are  in 
some  way  related  to  them.  Thither  came  Solon,  who 
was  received  by  them  with  great  honor;  and  he  asked  the 
priests,  who  were  most  skilful  in  such  matters,  about 
antiquity,  and  made  the  discovery  that  neither  he  nor 
any  other  Hellene  knew  anything  worth  mentioning 
about  the  times  of  old. 

"On  one  occasion,  when  he  was  drawing  them  on  to 


346         VOLCANOES  AND  EARTHQUAKES 

speak  of  antiquity,  he  began  to  tell  about  the  most  an- 
cient things  in  our  part  of  the  world — about  Phoroneus, 
who  is  called  'the  first/  and  about  Niobe;  and,  after  the 
Deluge,  to  tell  of  the  lives  of  Deucalian  and  Pyrrha;  and 
he  traced  the  genealogy  of  their  descendants,  and  at- 
tempted to  reckon  how  many  years  old  were  the  events  of 
which  he  was  speaking,  and  to  give  the  dates.  Thereupon, 
one  of  the  priests,  who  was  of  very  great  age,  said:  'O 
Solon,  Solon,  you  Hellenes  are  but  children,  and  there  is 
never  an  old  man  who  is  an  Hellene.'  Solon,  hearing  this, 
said,  'What  do  you  mean?'  'I  mean  to  say,'  he  replied, 
'that  in  mind  you  are  all  young;  there  is  no  old  opinion 
handed  down  among  you  by  ancient  traditions,  nor  any 
science  which  is  hoary  with  age.  And  I  will  tell  you  the 
reason  of  this:  there  have  been,  and  there  will  be  again, 
many  destructions  of  mankind  arising  out  of  many  causes. 

"'There  is  a  story  which  even  you  have  preserved,  that 
once  upon  a  time  Phaethon,  the  son  of  Helios,  having 
yoked  the  steeds  in  his  father's  chariot,  because  he  was 
not  able  to  drive  them  in  the  path  of  his  father,  burnt  up 
all  that  was  upon  the  earth,  and  was  himself  destroyed 
by  a  thunder-bolt.  Now,  this  has  the  form  of  a  myth, 
but  really  signifies  a  declination  of  the  bodies  moving 
around  the  earth,  and  in  the  heavens,  and  a  great  con- 
flagration of  things  upon  the  earth  recurring  at  long  in- 
tervals of  time:  when  this  happens,  those  who  live  upon 
the  mountains  and  in  dry  and  lofty  places  are  more  liable 
to  destruction  than  those  who  dwell  by  rivers  or  on  the 
sea-shore;  and  from  this  calamity  the  Nile,  who  is  our 
never-failing  savior,  saves  and  delivers  us. 

"  'When,  on  the  other  hand,  the  gods  purge  the  earth 
with  a  deluge  of  water,  among  you  herdsmen  and  shep- 
herds on  the  mountains  are  the  survivors,  whereas  those 
of  you  who  live  in  cities  are  carried  by  the  rivers  into  the 


PLATO'S  ACCOUNT  OF  ATLANTIS          347 

sea;  but  in  this  country  neither  at  that  time  nor  at  any 
other  does  the  water  come  up  from  below,  for  which  rea- 
son the  things  preserved  here  are  said  to  be  the  oldest. 
The  fact  is,  that  wherever  the  extremity  of  winter  frost 
or  of  summer  sun  does  not  prevent,  the  human  race  is 
always  increasing  at  times,  and  at  other  times  diminish- 
ing in  numbers.  And  whatever  happened  either  in  your 
country  or  in  ours,  or  in  any  other  regions  of  which  we  are 
informed — if  any  action  which  is  noble  or  great,  or  in  any 
other  way  remarkable  has  taken  place,  all  that  has  been 
written  down  of  old,  and  is  preserved  in  our  temples; 
whereas  you  and  other  nations  are  just  being  provided 
with  letters  and  the  other  things  which  States  require; 
and  then,  at  the  usual  period,  the  stream  from  heaven 
descends  like  a  pestilence,  and  leaves  only  those  of  you 
who  are  destitute  of  letters  and  education;  and  thus  you 
have  to  begin  all  over  again  as  children,  and  know  nothing 
of  what  happened  in  ancient  times,  either  among  us  or 
among  yourselves. 

"  'As  for  those  genealogies  of  yours  which  you  have 
recounted  to  us,  Solon,  they  are  no  better  than  the  tales 
of  children;  for,  in  the  first  place,  you  remember  one  deluge 
only,  whereas  there  were  many  of  them,  and,  in  the  next 
place,  you  do  not  know  that  there  dwelt  in  your  land  the 
fairest  and  noblest  race  of  men  which  ever  lived,  of  whom 
you  and  your  whole  city  are  but  a  seed  or  remnant.  And 
this  was  unknown  to  you,  because  for  many  generations 
the  survivors  of  that  destruction  died  and  made  no  sign. 
For  there  was  a  time,  Solon,  before  that  great  deluge 
of  all,  when  the  city  which  now  is  Athens,  was  first  in 
war,  and  was  preeminent  for  the  excellence  of  her  laws, 
and  is  said  to  have  performed  the  noblest  deeds,  and  to 
have  had  the  fairest  constitution  of  any  of  which  tradition 
tells,  under  the  face  of  heaven.' 


348          VOLCANOES  AND  EARTHQUAKES 

"Solon  marvelled  at  this  and  earnestly  requested  the 
priest  to  inform  him  exactly  and  in  order  about  these 
former  citizens.  'You  are  welcome  to  hear  about  them, 
Solon,'  said  the  priest,  'both  for  your  own  sake  and  for 
that  of  the  city;  and,  above  all,  for  the  sake  of  the  goddess 
who  is  the  common  patron  and  protector  and  educator 
of  both  our  cities.  She  founded  your  city  a  thousand 
years  before  ours,  receiving  from  the  Earth  and  Hephaes- 
tus the  seed  of  your  race,  and  then  she  founded  ours,  the 
constitution  of  which  is  set  down  in  our  sacred  registers 
as  8,000  years  old.  As  touching  the  citizens  of  9,000  years 
ago,  I  will  briefly  inform  you  of  their  laws  and  of  the  no- 
blest of  their  actions;  and  the  exact  particulars  of  the 
whole  we  will  hereafter  go  through  at  our  leisure  in  the 
sacred  registers  themselves.  If  you  compare  these  very 
laws  with  your  own,  you  will  find  that  many  of  ours  are 
the  counterpart  of  yours,  as  they  were  in  the  olden  time. 

"  '  In  the  first  place,  there  is  the  caste  of  priests,  which 
is  separated  from  all  the  others;  next  there  are  the  arti- 
ficers, who  exercise  their  several  crafts  by  themselves, 
and  without  admixture  of  any  other,  and  also  there  is 
the  class  of  shepherds  and  that  of  hunters,  as  well  as  that 
of  husbandmen;  and  you  will  observe,  too,  that  the  war- 
riors in  Egypt  are  separated  from  all  the  other  classes, 
and  are  commanded  by  the  law  only  to  engage  in  war. 
Moreover,  the  weapons  with  which  they  are  equipped 
are  shields  and  spears,  and  this  the  goddess  taught  first 
among  you,  and  then  in  Asiatic  countries,  and  we  among 
the  Asiatics  first  adopted. 

"  'Then,  as  to  wisdom,  do  you  observe,  what  care  the 
law  took  from  the  very  first,  searching  out  and  compre- 
hending the  whole  order  of  things  down  to  prophecy  and 
medicine  (the  latter  with  a  view  to  health);  and  out  of 
these  divine  elements  drawing  what  was  needful  for 


PLATO'S  ACCOUNT  OF  ATLANTIS          349 

human  life,  and  adding  every  sort  of  knowledge  which 
was  connected  with  them.  All  this  order  and  arrangement 
the  goddess  first  imparted  to  you  when  establishing  your 
city;  and  she  chose  the  spot  of  earth  in  which  you  were 
born,  because  she  saw  that  the  happy  temperament  of 
the  seasons  in  that  land  would  produce  the  wisest  of  men. 

"  'Wherefore  the  goddess,  who  was  a  lover  both  of 
war  and  of  wisdom,  selected,  and  first  of  all  settled  that 
spot  which  was  the  most  likely  to  produce  men  likest 
herself.  And  there  you  dwelt,  having  such  laws  as  these 
and  still  better  ones,  and  excelled  all  mankind  in  all 
virtue,  as  became  the  children  and  disciples  of  the  gods. 
Many  great  and  wonderful  deeds  are  recorded  of  your 
State  in  our  histories;  but  one  of  them  exceeds  all  the  rest 
in  greatness  and  valor;  for  these  histories  tell  of  a  mighty 
power  which  was  agressing  wantonly  against  the  whole 
of  Europe  and  Asia,  and  to  which  your  city  put  an  end. 

"  'This  power  came  forth  out  of  the  Atlantic  Ocean, 
for  in  those  days  the  Atlantic  was  navigable;  and  there 
was  an  island  situated  in  front  of  the  straits  which  you 
call  the  Columns  of  Heracles:  the  island  was  larger  than 
Libya  and  Asia  put  together,  and  was  the  way  to  other 
islands,  and  from  the  island  you  might  pass  through  the 
whole  of  the  opposite  continent  which  surrounded  the 
true  ocean;  for  this  sea  which  is  within  the  Straits  of 
Heracles  is  only  a  harbor,  having  a  narrow  entrance,  but 
that  other  is  a  real  sea,  and  the  surrounding  land  may  be 
most  truly  called  a  continent.  Now,  in  the  island  of 
Atlantis  there  was  a  great  and  wonderful  empire,  which 
had  rule  over  the  whole  island  and  several  others,  as  well 
as  over  parts  of  the  continent;  and,  besides  these,  they 
subjected  the  parts  of  Libya  within  the  Columns  of 
Heracles  as  far  as  Egypt,  and  of  Europe  as  far  as  Tyrr- 
henia. 


350          VOLCANOES  AND  EARTHQUAKES 

"  'That  vast  power,  thus  gathered  into  one,  endeavored 
to  subdue  at  one  blow  our  country  and  yours,  and  the 
whole  of  the  land  which  was  within  the  straits;  and  then, 
Solon,  your  country  shone  forth,  in  the  excellence  of  her 
virtue  and  strength,  among  all  mankind,  for  she  was  the 
first  in  courage  and  military  skill,  and  was  the  leader 
of  the  Hellenes.  And  when  the  rest  fell  off  from  her, 
being  compelled  to  stand  alone,  after  having  undergone 
the  very  extremity  of  danger,  she  defeated  and  triumphed 
over  the  invaders,  and  preserved  from  slavery  those  who 
were  not  yet  subjected,  and  freely  liberated  all  the  others 
who  dwelt  within  the  limits  of  Heracles.  But  afterward 
there  occurred  violent  earthquakes  and  floods,  and  in  a 
single  day  and  night  of  rain  all  your  warlike  men  in  a  body 
sunk  into  the  earth,  and  the  island  of  Atlantis  in  like 
manner  disappeared,  and  was  sunk  beneath  the  sea. 
And  that  is  the  reason  why  the  sea  in  those  parts  is  im- 
passable and  impenetrable,  because  there  is  such  a  quan- 
tity of  shallow  mud  in  the  way;  and  this  was  caused  by 
the  subsidence  of  the  island.'  ('Plato's  Dialogues,'  ii, 
517,  Timseus.)  .... 

"  But  in  addition  to  the  gods  whom  you  have  mentioned, 
I  would  specially  invoke  Mnemosyne;  for  all  the  important 
part  of  what  I  have  to  tell  is  dependent  on  her  favor,  and 
if  I  can  recollect  and  recite  enough  of  what  was  said  by 
the  priests,  and  brought  hither  by  Solon,  I  doubt  not 
that  I  shall  satisfy  the  requirements  of  this  theatre.  To 
that  task,  then,  I  will  at  once  address  myself. 

"  Let  me  begin  by  observing  first  of  all  that  nine  thou- 
sand was  the  sum  of  years  which  had  elapsed  since  the 
war  which  was  said  to  have  taken  place  between  all  those 
who  dwelt  outside  the  Pillars  of  Heracles  and  those  who 
dwelt  within  them.  This  war  I  am  now  to  describe.  Of 
the  combatants  on  the  one  side  the  city  of  Athens  waa 


PLATO'S  ACCOUNT  OF  ATLANTIS          351 

reported  to  have  been  the  ruler,  and  to  have  directed  the 
contest;  the  combatants  on  the  other  side  were  led  by 
the  kings  of  the  islands  of  Atlantis,  which,  as  I  was  saying, 
once  had  an  extent  greater  than  that  of  Libya  and  Asia; 
and,  when  afterwards  sunk  by  an  earthquake,  became 
an  impassable  barrier  of  mud  to  voyagers  sailing  from 
hence  to  the  ocean.  The  progress  of  the  history  will 
unfold  the  various  tribes  of  barbarians  and  Hellenes 
which  then  existed,  as  they  successively  appear  on  the 
scene;  but  I  must  begin  by  describing,  first  of  all,  the 
Athenians  as  they  were  in  that  day,  and  their  enemies  who 
fought  with  them;  and  I  shall  have  to  tell  of  the  power 
and  form  of  government  of  both  of  them.  Let  us  give 
the  precedence  to  Athens.  .  .  . 

"Many  great  deluges  have  taken  place  during  the  nine 
thousand  years,  for  that  is  the  number  of  years  which 
have  elapsed  since  the  time  of  which  I  am  speaking;  and 
in  all  the  ages  and  changes  of  things  there  has  never  been 
any  settlement  of  the  earth  flowing  down  from  the  moun- 
tains, as  in  other  places,  which  is  worth  speaking  of;  it 
has  always  been  carried  round  in  a  circle,  and  disappeared 
in  the  depths  below.  The  consequence  is  that,  in  com- 
parison with  what  then  was,  there  are  remaining  in  small 
islets  only  the  bones  of  the  wasted  body,  as  they  may  be 
called,  all  the  richer  and  softer  parts  of  the  soil  having 
fallen  away,  and  the  mere  skeleton  of  the  country  being 
left.  .  .  . 

"And  next,  if  I  have  not  forgotten  what  I  heard  when 
I  was  a  child,  I  will  impart  to  you  the  character  and  origin 
of  their  adversaries;  for  friends  should  not  keep  their 
stories  to  themselves,  but  have  them  in  common.  Yet, 
before  proceeding  further  in  the  narrative,  I  ought  to 
warn  you  that  you  must  not  be  surprised,  if  you  should 
hear  Hellenic  names  given  to  foreigners.  I  will  tell  you 


352         VOLCANOES  AND  EARTHQUAKES 

the  reason  of  this:  Solon,  who  was  intending  to  use  the 
tale  for  his  poem,  made  an  investigation  into  the  meaning 
of  the  names,  and  found  that  the  early  Egyptians,  in 
writing  them  down,  had  translated  them  into  their  own 
language,  and  he  recovered  the  meaning  of  the  several 
names  and  retranslated  them,  and  copied  them  out  again 
in  our  language.  My  great-grandfather,  Dropidas,  had 
the  original  writing,  which  is  still  in  my  possession,  and 
was  carefully  studied  by  me  when  I  was  a  child.  There- 
fore, if  you  hear  names  such  as  are  used  in  this  country, 
you  must  not  be  surprised,  for  I  have  told  you  the  reason 
of  them. 

"The  tale,  which  was  of  great  length,  began  as  follows: 
I  have  before  remarked,  in  speaking  of  the  allotments  of 
the  gods,  that  they  distributed  the  whole  earth  into  por- 
tions differing  in  extent,  and  made  themselves  temples 
and  sacrifices.  And  Poseidon,  receiving  for  his  lot  the 
island  of  Atlantis,  begat  children  by  a  mortal  woman, 
and  settled  them  in  a  part  of  the  island  which  I  will  pro- 
ceed to  describe.  On  the  side  toward  the  sea,  and  in  the 
centre  of  the  whole  island,  there  was  a  plain  which  is  said 
to  have  been  the  fairest  of  all  plains,  and  very  fertile. 
Near  the  plain,  and  also  in  the  centre  of  the  island,  at  a 
distance  of  about  fifty  stadia,  there  was  a  mountain,  not 
very  high  on  any  side.  In  this  mountain  there  dwelt  one 
of  the  earth-born  primeval  men  of  that  country,  whose 
name  was  Evenor,  and  he  had  a  wife  named  Leucippe,  and 
they  had  an  only  daughter,  who  was  named  Cleito. 

"The  maiden  was  growing  up  to  womanhood  when  her 
father  and  mother  died;  Poseidon  fell  in  love  with  her, 
and  had  intercourse  with  her;  and,  breaking  the  ground, 
enclosed  the  hill  in  which  she  lived  all  around,  making 
alternate  zones  of  sea  and  land,  larger  and  smaller,  en- 
circling one  another;  there  were  two  of  land  and  three  of 


PLATO'S  ACCOUNT   OF  ATLANTIS         353 

water,  which  he  turned  as  with  a  lathe  out  of  the  centre 
of  the  island,  equidistant  every  way,  so  that  no  man  could 
get  to  the  island,  for  ships  and  voyagers  were  not  yet 
heard  of.  He  himself,  as  he  was  a  god,  found  no  difficulty 
in  making  special  arrangements  for  the  centre  island, 
bringing  two  streams  of  water  under  the  earth,  which  he 
caused  to  ascend  as  springs,  one  of  warm  water  and  the 
other  of  cold,  and  making  every  variety  of  food  to  spring 
up  abundantly  in  the  earth.  He  also  begat  and  brought 
up  five  pairs  of  male  children,  dividing  the  island  of  At- 
lantis into  ten  portions;  he  gave  to  the  first-born  of  the 
eldest  pair  his  mother's  dwelling  and  the  surrounding 
allotment,  which  was  the  largest  and  best,  and  made  him 
king  over  the  rest;  the  others  he  made  princes,  and  gave 
them  rule  over  many  men  and  a  large  territory. 

"He  named  them  all:  the  eldest,  who  was  king,  he 
named  Atlas,  and  from  him  the  whole  island  and  the 
ocean  received  the  name  of  Atlantic.  To  his  twin  brother, 
who  was  born  after  him,  and  obtained  as  his  lot  the 
extremity  of  the  island  toward  the  Pillars  of  Heracles,  as 
far  as  the  country  which  is  still  called  the  region  of  Gades 
in  that  part  of  the  world,  he  gave  the  name  which  in  the 
Hellenic  language  is  Eumelus,  in  the  language  of  the  coun- 
try which  is  named  after  him,  Gadeirus.  Of  the  second 
pair  of  twins,  he  called  one  Ampheres  and  the  other 
Evsemon.  To  the  third  pair  of  twins  he  gave  the  name 
Mneseus  to  the  elder,  and  Autochthon  to  the  one  who 
followed  him.  Of  the  fourth  pair  of  twins  he  called  the 
elder  Elasippus  and  the  younger  Mestor.  And  of  the  fifth 
pair  he  gave  to  the  elder  the  name  of  Azaes,  and  to  the 
younger  Diaprepes. 

"All  these  and  their  descendants  were  the  inhabitants 
and  rulers  of  divers  islands  in  the  open  sea;  and  also,  as 
has  been  already  said,  they  held  sway  in  the  other  direc- 


354         VOLCANOES  AND  EARTHQUAKES 

tion  over  the  country  within  the  Pillars  as  far  as  Egypt 
and  Tyrrhenia.  Now  Atlas  had  a  numerous  and  honorable 
family,  and  his  eldest  branch  always  retained  the  kingdom, 
which  the  eldest  son  handed  on  to  his  eldest  for  many 
generations;  and  they  had  such  an  amount  of  wealth  as 
was  never  before  possessed  by  kings  and  potentates,  and 
is  not  likely  ever  to  be  again,  and  they  were  furnished  with 
everything  which  they  could  desire  both  in  city  and 
country.  For,  because  of  the  greatness  of  their  empire, 
many  things  were  brought  to  them  from  foreign  countries, 
and  the  island  itself  provided  much  of  what  was  required 
by  them  for  the  uses  of  life. 

"  In  the  first  place,  they  dug  out  of  the  earth  whatever 
was  to  be  found  there,  mineral  as  well  as  metal,  and  that 
which  is  now  only  a  name,  and  was  then  something  more 
than  a  name — orichalcum — was  dug  out  of  the  earth 
in  many  parts  of  the  island,  and,  with  the  exception  of 
gold,  was  esteemed  the  most  precious  of  metals  among 
the  men  of  those  days.  There  was  an  abundance  of  wood 
for  carpenters'  work,  and  sufficient  maintenance  for  tame 
and  wild  animals.  Moreover,  there  were  a  great  number 
of  elephants  in  the  island,  and  there  was  provision  for 
animals  of  every  kind,  both  for  those  who  live  in  lakes  and 
marshes  and  rivers,  and  also  for  those  which  live  in 
mountains,  and  on  plains,  and  therefore  for  the  animal 
which  is  the  largest  and  most  voracious  of  them. 

"Also  whatever  fragrant  things  there  are  in  the  earth, 
whether  roots,  or  herbage,  or  woods,  or  distilling  drops 
of  flowers,  or  fruits,  grew  and  thrived  in  that  land;  and 
again,  the  cultivated  fruit  of  the  earth,  both  the  dry 
edible  fruit  and  other  species  of  food,  which  we  call  by 
the  general  name  of  legumes,  and  the  fruits  having  a  hard 
rind,  affording  drinks,  and  meats,  and  ointments,  and 
good  store  of  chestnuts  and  the  Hke,  which  may  be  used 


PLATO'S  ACCOUNT  OF  ATLANTIS         355 

to  play  with,  and  are  fruits  which  spoil  with  keeping — 
and  the  pleasant  kinds  of  dessert  which  console  us  after 
dinner,  when  we  are  full  and  tired  of  eating — all  these 
that  sacred  island  lying  beneath  the  sun  brought  forth 
fair  and  wondrous  in  infinite  abundance. 

"All  these  things  they  received  from  the  earth,  and 
they  employed  themselves  in  constructing  their  temples, 
and  palaces,  and  harbors  and  docks;  and  they  arranged 
the  whole  country  in  the  following  manner:  first  of  all 
they  bridged  over  the  zones  of  sea  which  surrounded  the 
ancient  metropolis,  and  made  a  passage  into  and  out  of 
the  royal  palace;  and  then  they  began  to  build  the  palace 
in  the  habitation  of  the  god  and  of  their  ancestors.  This 
they  continued  to  ornament  in  successive  generations, 
every  king  surpassing  the  one  who  came  before  him  to 
the  utmost  of  his  power,  until  they  made  the  building  a 
marvel  to  behold  for  size  and  for  beauty. 

"And,  beginning  from  the  sea,  they  dug  a  canal  three 
hundred  feet  in  width  and  one  hundred  feet  in  depth, 
and  fifty  stadia  in  length,  which  they  carried  through 
to  the  outermost  zone,  making  a  passage  from  the  sea  up 
to  this,  which  became  a  harbor,  and  leaving  an  opening 
sufficient  to  enable  the  largest  vessels  to  find  ingress. 
Moreover,  they  divided  the  zones  of  land  which  parted 
the  zones  of  sea,  constructing  bridges  of  such  a  width  as 
would  leave  a  passage  for  a  single  trireme  to  pass  out  of 
one  into  another,  and  roofed  them  over;  and  there  was 
a  way  underneath  for  the  ships,  for  the  banks  of  the  zones 
wTere  raised  considerably  above  the  water. 

"Now  the  largest  of  the  zones  into  which  a  passage  was 
cut  from  the  sea  was  three  stadia  in  breadth,  and  the  zone 
of  land  which  came  next  of  equal  breadth;  but  the  next 
two,  as  well  a  zone  of  water  as  of  land,  were  two  stadia, 
and  the  one  which  surrounded  the  central  island  was  a 


356         VOLCANOES  AND  EARTHQUAKES 

stadium  only  in  width.  The  island  in  which  the  palace 
was  situated  had  a  diameter  of  five  stadia.  This,  and  the 
zones  and  the  bridge,  which  was  the  sixth  part  of  a  stadium 
in  width,  they  surrounded  by  a  stone  wall,  on  either  side 
placing  towers,  and  gates  on  the  bridges  where  the  sea 
passed  in.  The  stone  which  was  used  in  the  work  they 
quarried  from  underneath  the  centre  island  and  from 
underneath  the  zones,  on  the  outer  as  well  as  the  inner 
side.  One  kind  of  stone  was  white,  another  black,  and 
a  third  red;  as  they  quarried,  they  at  the  same  time 
hollowed  out  decks,  double  within,  having  roofs  formed 
out  of  the  native  rock. 

"  Some  of  their  buildings  were  simple,  but  in  others 
they  put  together  different  stones,  which  they  inter- 
mingled for  the  sake  of  ornament,  to  be  a  natural  source 
of  delight.  The  entire  circuit  of  the  wall  which  went 
around  the  outermost  one  they  covered  with  a  coating 
of  brass,  and  the  circuit  of  the  next  wall  they  coated  with 
tin,  and  the  third,  which  encompassed  the  citadel,  flashed 
with  the  red  light  of  orichalcum.  The  palace  in  the 
interior  of  the  citadel  was  constructed  in  this  wise:  in 
the  centre  was  a  holy  temple,  dedicated  to  Cleito  and 
Poseidon,  which  remained  inaccessible,  and  was  sur- 
rounded by  an  enclosure  of  gold;  this  was  the  spot  in 
which  was  originally  begotten  the  race  of  ten  princes, 
and  thither  they  annually  brought  the  fruits  of  the  earth 
in  their  season  from  all  the  ten  portions,  and  performed 
sacrifices  to  each  of  them. 

"Here,  too,  was  Poseidon's  own  temple,  of  a  stadium 
in  length  and  half  a  stadium  in  width,  and  of  a  propor- 
tionate height,  having  a  sort  of  barbaric  splendor.  All 
the  outside  of  the  temple,  with  the  exception  of  the 
pinnacles,  they  covered  with  silver,  and  the  pinnacles 
with  gold.  In  the  interior  of  the  temple  the  roof  was 


PLATO'S  ACCOUNT  OF  ATLANTIS          357 

of  ivory,  adorned  everywhere  with  gold  and  silver  and 
orichalcum;  all  the  other  parts  of  the  walls  and  pillars 
and  floor  they  lined  with  orichalcum.  In  the  temple 
they  placed  statues  of  gold:  there  was  the  god  himself 
standing  in  a  chariot — the  charioteer  of  six  winged 
horses — and  of  such  a  size  that  he  touched  the  roof  of 
the  building  with  his  head;  around  him  were  a  hundred 
Nereids  riding  on  dolphins,  for  such  was  thought  to  be 
the  number  of  them  in  that  day. 

"There  were  also  in  the  interior  of  the  temple  other 
images  which  had  been  dedicated  by  private  individuals. 
And  around  the  temple,  on  the  outside,  were  placed 
statues  of  gold  of  all  the  ten  kings  and  of  their  wives; 
and  there  were  many  other  great  offerings,  both  of  kings 
and  of  private  individuals,  coming  both  from  the  city 
itself  and  the  foreign  cities  over  which  they  held  sway. 
There  was  an  altar,  too,  which  in  size  and  workmanship 
corresponded  to  the  rest  of  the  work,  and  there  were 
palaces  in  like  manner  which  answered  to  the  greatness 
of  the  kingdom  and  the  glory  of  the  temple. 

"In  the  next  place,  they  used  fountains  both  of  gold 
and  hot  springs.  These  were  very  abundant,  and  both 
kinds  wonderfully  adapted  to  use  by  reason  of  the  sweet- 
ness and  excellence  of  their  waters.  They  constructed 
buildings  about  them,  and  planted  suitable  trees;  also 
cisterns,  some  open  to  the  heaven,  others  which  they 
roofed  over,  to  be  used  in  winter  as  warm  baths:  there 
were  the  king's  baths,  and  the  baths  of  private  persons, 
which  were  kept  apart;  also  separate  baths  for  women, 
and  others  again  for  horses  and  cattle,  and  to  them  they 
gave  as  much  adornment  as  was  suitable  for  them.  The 
water  which  ran  off  they  carried,  some  to  the  grove  of 
Poseidon,  where  were  growing  all  manner  of  trees  of 
wonderful  height  and  beauty,  owing  to  the  excellence 


358          VOLCANOES  AND  EARTHQUAKES 

of  the  soil;  the  remainder  was  conveyed  by  aqueducts 
which  passed  over  the  bridges  to  the  outer  circles:  and 
there  were  many  temples  built  and  dedicated  to  many 
gods;  also  gardens  and  places  of  exercise,  some  for  men, 
and  some  set  apart  for  horses,  in  both  of  the  two  islands 
formed  by  the  zones;  and  in  the  centre  of  the  larger 
of  the  two,  there  was  a  racecourse  of  a  stadium  in  width, 
and  in  length  allowed  to  extend  all  round  the  island, 
for  horses  to  race  in. 

"Also  there  were  guard-houses  at  intervals  for  the 
body-guard,  the  more  trusted  of  whom  had  their  duties 
appointed  to  them  in  the  lesser  zone,  which  was  nearer 
the  Acropolis;  while  the  most  trusted  of  all  had  houses 
given  them  within  the  citadel,  and  about  the  persons  of 
the  kings.  The  docks  were  full  of  triremes  and  naval 
stores,  and  all  things  were  quite  ready  for  use.  Enough 
of  the  plan  of  the  royal  palace.  Crossing  the  outer  har- 
bors, which  were  three  in  number,  you  would  come  to  a 
wall  which  began  at  the  sea  and  went  all  round;  this 
was  everywhere  distant  fifty  stadia  from  the  largest  zone 
and  harbor,  and  enclosed  the  whole,  meeting  at  the 
mouth  of  the  channel  toward  the  sea. 

"The  entire  area  was  densely  crowded  with  habitations; 
and  the  canal  and  the  largest  of  the  harbors  were  full  of 
vessels,  and  merchants  coming  from  all  parts,  who,  from 
their  numbers,  kept  up  a  multitudinous  sound  of  human 
voices  and  din  of  all  sorts,  night  and  day.  I  have  repeated 
his  descriptions  of  the  city  and  the  parts  about  the  ancient 
palace  nearly  as  he  gave  them,  and  now  I  must  endeavor 
to  describe  the  nature  and  arrangement  of  the  rest  of 
the  country.  The  whole  country  was  described  as  being 
very  lofty  and  precipitous  on  the  side  of  the  sea,  but  the 
country  immediately  about  and  surrounding  the  city 
was  a  level  plain,  itself  surrounded  by  mountains  which 


PLATO'S  ACCOUNT  OF  ATLANTIS         359 

descended  toward  the  sea;  it  was  smooth  and  even,  but 
of  an  oblong  shape,  extending  in  one  direction  three 
thousand  stadia,  and  going  up  the  country  from  the  sea 
through  the  centre  of  the  island  two  thousand  stadia; 
the  whole  region  of  the  island  lies  toward  the  south, 
and  is  sheltered  from  the  north. 

"The  surrounding  mountains  were  celebrated  for  their 
number  and  size  and  beauty,  in  which  they  exceeded 
all  that  are  now  to  be  seen  anywhere;  having  in  them  also 
many  wealthy  inhabited  villages,  and  rivers  and  lakes, 
and  meadows  supplying  food  enough  for  every  animal, 
wild  or  tame,  and  wood  of  various  sorts,  abundant  for 
every  kind  of  work.  I  will  now  describe  the  plain,  which 
had  been  cultivated  during  many  ages  by  many  genera- 
tions of  kings.  It  was  rectangular,  and  for  the  most 
part  straight  and  oblong;  and  what  it  wanted  of  the 
straight  line  followed  the  line  of  the  circular  ditch.  The 
depth  and  width  and  length  of  this  ditch  were  incredible, 
and  gave  the  impression  that  such  a  work,  in  addition 
to  so  many  other  works,  could  hardly  have  been  wrought 
by  the  hand  of  man.  But  I  must  say  what  I  have  heard. 

"It  was  excavated  to  the  depth  of  a  hundred  feet, 
and  its  breadth  was  a  stadium  everywhere;  it  was  carried 
round  the  whole  of  the  plain,  and  was  ten  thousand  stadia 
in  length.  It  received  the  streams  which  came  down 
the  mountains,  and  winding  round  the  plain,  and  touch- 
ing the  city  at  various  points,  was  there  let  off  into  the 
sea.  From  above,  likewise,  straight  canals  of  a  hundred 
feet  in  width  were  cut  in  the  plain,  and  again  let  off  into 
the  ditch,  toward  the  sea.  These  canals  were  at  intervals 
of  a  hundred  stadia,  and  by  them  they  brought  down 
the  wood  from  the  mountains  to  the  city,  and  conveyed 
the  fruits  of  the  earth  in  ships,  cutting  transverse  pas- 
sages from  one  canal  into  another,  and  to  the  city.  Twice 


360         VOLCANOES  AND  EARTHQUAKES 

in  the  year  they  gathered  the  fruits  of  the  earth — in 
winter  having  the  benefit  of  the  rains,  and  in  summer 
introducing  the  water  of  the  canals.  As  to  the  population, 
each  of  the  lots  in  the  plain  had  an  appointed  chief  of 
men  who  were  fit  for  military  service,  and  the  size  of  the 
lot  was  to  be  a  square  of  ten  stadia  each  way,  and  the 
total  number  of  all  the  lots  was  sixty  thousand. 

"And  of  the  inhabitants,  of  the  mountains  and  of  the 
rest  of  the  country  there  was  also  a  vast  multitude  having 
leaders,  to  whom  they  were  assigned  according  to  their 
dwellings  and  villages.  The  leader  was  required  to  fur- 
nish for  the  wars  the  sixth  portion  of  a  war-chariot,  so 
as  to  make  up  a  total  of  ten  thousand  chariots;  also  two 
horses  and  riders  upon  them,  and  a  light  chariot  without 
a  seat,  accompanied  by  a  fighting  man  on  foot  carrying 
a  small  shield,  and  having  a  charioteer  mounted  to  guide 
the  horses;  also,  he  was  bound  to  furnish  two  heavy- 
armed  men,  two  archers,  two  slingers,  three  stone-shooters, 
and  three  javelin  men,  who  were  skirmishers,  and  four 
sailors,  to  make  up  a  complement  of  twelve  hundred  ships. 
Such  was  the  order  of  war  in  the  royal  city. 

"That  of  the  other  nine  governments  was  different 
in  each  of  them,  and  would  be  wearisome  to  narrate. 
As  to  offices  and  honors  the  following  was  the  arrange- 
ment from  the  first:  each  of  the  ten  kings,  in  his  own 
division  and  in  his  own  city,  had  the  absolute  control 
of  the  citizens,  and  in  many  cases,  of  the  laws,  punishing 
and  slaying  whomsoever  he  would. 

"  Now  the  relations  of  their  governments  to  one  another 
were  regulated  by  the  injunctions  of  Poseidon  as  the  law 
had  handed  them  down.  These  were  inscribed  by  the 
first  men  on  a  column  of  orichalcum,  which  was  situated 
in  the  middle  of  the  island,  at  the  temple  of  Poseidon, 
whither  the  people  were  gathered  together  every  fifth 


PLATO'S  ACCOUNT  OF  ATLANTIS          361 

and  sixth  years  alternately,  thus  giving  equal  honor  to 
the  odd  and  to  the  even  number.  And  when  they  were 
gathered  together  they  consulted  about  public  affairs, 
and  inquired  if  any  one  had  transgressed  in  anything, 
and  passed  judgment  on  him  accordingly — and  before 
they  passed  judgment  they  gave  their  pledges  to  one 
another  in  this  wise: 

"There  were  bulls  who  had  the  range  of  the  temple 
of  Poseidon;  and  the  ten  who  were  left  alone  in  the  temple, 
after  they  had  offered  prayers  to  the  gods  that  they 
might  take  the  sacrifices  which  were  acceptable  to  them, 
hunted  the  bulls  without  weapons,  but  with  staves  and 
nooses;  and  the  bull  which  they  caught  they  led  up  to 
the  column.  The  victim  was  then  struck  on  the  head 
by  them,  and  slain  over  the  sacred  inscription.  Now 
on  the  column,  besides  the  law,  there  was  inscribed  an 
oath  invoking  mighty  curses  on  the  disobedient.  When, 
therefore,  after  offering  sacrifices  according  to  their 
customs,  they  had  burnt  the  limbs  of  the  bull,  they 
mingled  a  cup  and  cast  in  a  clot  of  blood  for  each  of  them. 
The  rest  of  the  victim  they  took  to  the  fire,  after  having 
made  a  purification  of  the  column  all  round. 

"They  then  drew  from  the  cup  in  golden  vessels,  and, 
pouring  a  libation  on  the  fire,  they  swore  that  they  would 
judge  according  to  the  laws  on  the  column,  and  would 
punish  any  one  who  had  previously  transgressed,  and 
that  for  the  future  they  would  not,  if  they  could  help, 
transgress  any  of  the  inscriptions,  and  would  not  com- 
mand, or  obey  any  ruler  who  commanded  them,  to  act 
otherwise  than  according  to  the  laws  of  their  father 
Poseidon. 

"This  was  the  prayer  which  each  of  them  offered  up 
for  himself  and  for  his  family,  at  the  same  time  drinking, 
and  dedicating  the  vessel  in  the  temple  of  the  god;  and, 


362         VOLCANOES  AND  EARTHQUAKES 

after  spending  some  necessary  time  at  supper,  when 
darkness  came  on  and  the  fire  about  the  sacrifice  was  cool, 
all  of  them  put  on  most  beautiful  azure  robes,  and,  sit- 
ting on  the  ground  at  night  near  the  embers  of  the  sacri- 
fices on  which  they  had  sworn,  and  extinguishing  all 
the  fires  about  the  temple,  they  received  and  gave  judg- 
ment, if  any  of  them  had  any  accusation  to  bring  against 
any  one;  and,  when  they  had  given  judgment,  at  day- 
break they  wrote  down  their  sentences  on  a  golden  tablet, 
and  deposited  them  as  memorials  with  their  robes. 

"There  were  many  special  laws  which  the  several 
kings  had  inscribed  about  the  temple,  but  the  most  im- 
portant was  the  following:  that  they  were  not  to  take  up 
arms  against  one  another,  and  they  were  all  to  come  to 
the  rescue,  if  any  one  in  any  city  attempted  to  overthrow 
the  royal  house.  Like  their  ancestors,  they  were  to  de- 
liberate in  common  about  war  and  other  matters,  giving 
the  supremacy  to  the  family  of  Atlas;  and  the  king  was 
not  to  have  the  power  of  life  or  death  over  any  of  his 
kinsmen,  unless  he  had  the  assent  of  the  majority  of 
the  ten  kings. 

"Such  was  the  vast  power  which  the  god  settled  in 
the  lost  island  of  Atlantis;  and  this  he  afterward  directed 
against  our  land  on  the  following  pretext,  as  traditions 
tell.  For  many  generations,  as  long  as  the  divine  nature 
lasted  in  them,  they  were  obedient  to  the  laws,  and 
well-affectioned  toward  the  gods,  who  were  their  kinsmen, 
for  they  possessed  true  and  in  every  way  great  spirits, 
practicing  gentleness  and  wisdom  in  the  various  chances 
of  life,  and  in  their  intercourse  with  one  another. 

"They  despised  everything  but  virtue,  not  caring  for 
their  present  state  of  life,  and  thinking  lightly  on  the 
possession  of  gold,  and  other  property,  which  seemed 
only  a  burden  to  them;  neither  were  they  intoxicated 


PLATO'S  ACCOUNTS    OF    ATLANTIS        363 

by  luxury,  nor  did  wealth  deprive  them  of  their  self- 
control;  but  they  were  sober,  and  saw  clearly  that  all 
these  goods  are  increased  by  virtuous  friendship  with 
one  another,  and  that  by  excessive  zeal  for  them  and 
honor  of  them,  the  good  of  them  is  lost,  and  friendship 
perishes  with  them. 

"By  such  reflections,  and  by  the  continuance  in  them 
of  a  divine  nature,  all  that  which  we  have  described 
waxed  and  increased  in  them;  but  when  this  divine  por- 
tion began  to  fade  away  in  them,  and  became  diluted 
too  often,  and  with  too  much  of  the  mortal  admixture, 
and  the  human  nature  got  the  upper  hand,  then,  they 
being  unable  to  bear  their  fortune,  became  unseemly, 
and  to  him  who  had  an  eye  to  see,  they  began  to  appear 
base,  and  had  lost  the  fairest  of  their  precious  gifts; 
but  to  those  who  had  no  eye  to  see  the  true  happiness 
they  still  appeared  glorious  and  blessed  at  the  very  time 
when  they  were  filled  with  unrighteous  avarice  and  power. 
Zeus,  the  god  of  gods,  who  rules  with  law,  and  is  able 
to  see  into  such  things,  perceiving  that  an  honorable 
race  was  in  a  most  wretched  state,  and  wanting  to  inflict 
punishment  on  them,  that  they  might  be  chastened  and 
improved,  collected  all  the  gods  into  his  most  holy  habi- 
tation, which,  being  placed  in  the  centre  of  the  world, 
sees  all  things  that  partake  of  generations.  And  when 
he  had  called  them  together,  he  spake  as  follows:" 

The  story  abruptly  ends  here,  for  Plato  left  no  further 
record. 


CHAPTER  XXXIX 
NATURE'S  WARNING   OF  COMING   EARTHQUAKES 

That  there  are  signs  of  coming  earthquakes  which 
might  be  read  by  man,  had  he  sufficient  knowledge,  there 
would  seem  to  be  but  little  doubt.  These  phenomena 
follow  natural  laws  so  that  the  approach  of  an  earth- 
quake must  necessarily  be  in  a  definite  order  both  as 
regards  the  phenomena  which  precede  as  well  as  those 
which  follow  it.  There  should,  therefore,  be  signs  that 
would  enable  one  to  predict  its  coming,  although  it  must 
be  acknowledged  that  these  signs,  so  far  as  we  actually 
know,  are  indistinct. 

It  may  seem  to  the  unthinking  and  unobservant  that 
the  awful  catastrophe  of  an  earthquake  comes  entirely 
unheralded;  that,  apparently,  it  is  not  until  the  earth's 
surface  begins  to  rock  to  and  fro  under  the  mighty  forces 
that  are  causing  destruction  that  its  presence  can  be 
known.  There  are,  however,  many  reasons  for  believing 
that  in,  perhaps,  the  greatest  number  of  cases,  it  might 
have  been  foreseen,  if  greater  attention  had  been  given 
to  the  slight  indications  of  its  probable  approach  a  short 
time  before  its  occurrence. 

It  is  evident  that  the  conditions  of  great  pressure  or 
stress  in  the  earth's  crust  which  finally  result  in  a  dis- 
astrous earthquake  have  been  slowly  accumulating  for 
a  long  time,  and  that  when  the  pressure  at  last  reaches  a 
point  where  the  crust  has  to  yield  or  slip,  the  ground  is  sud- 
denly crushed  and  tossed  to  and  fro  while  vast  fissures 
[364] 


NATURE'S  WARNING  365 

and  chasms  are  produced  in  the  subterranean  regions. 
At  those  points  of  the  earth  immediately  above  or  in  the 
neighborhood  of  such  regions  it  is  possible  that  there  are 
many  signs  of  the  coming  quake;  and,  although  indis- 
tinguishable by  our  duller  senses,  are  readily  appreciated 
by  the  more  highly  developed  senses  of  the  lower  animals. 
Indeed,  had  we  accustomed  ourselves  to  reading  the 
various  indications  of  nature  as  the  lower  animals  have, 
we,  too,  might  be  able  to  read  these  warnings  of  the 
coming  earthquake. 

At  great  distances  from  the  place  where  the  earth- 
quake starts  there  would  necessarily  be  a  better  op- 
portunity for  predicting  its  approach.  As  already  stated, 
what  is  called  an  earthquake  does  not  consist  of  a  single 
shaking  of  the  ground,  but  of  a  highly  complex  series 
of  shakings.  According  to  Mallet,  the  following  waves 
start  at  the  same  time  from  the  place  of  origin  of  an 
earthquake,  when  located  on  the  bed  of  an  ocean;  i.  e., 
an  earth  sound  wave  and  a  earth  wave  constituting  the 
earth's  shake;  a  sound  wave  through  the  ocean,  another 
through  the  air;  a  sea  wave  called  by  him  a  forced  sea 
wave,  and  finally  the  great  sea  wave. 

These  waves  reach  a  distant  point  in  the  following 
order:  the  sound  wave  through  the  earth  and  the  great 
earthquake  or  shake  which  produces  the  damage.  Then 
a  smaller  sea  wave  called  the  forced  sea  wave.  This  is 
followed  almost  immediately  by  the  sound  wave  through 
the  sea.  Next  come  the  air  sound  wave  and  finally  the 
great  sea  wave;  which,  rushing  in  on  the  shore,  sweeps 
nearly  everything  before  it. 

In  other  words,  the  disturbances  produced  by  the 
great  earthquake  follow  in  this  order  of  sequence.  If, 
therefore,  the  great  earthquake  wave  proper  transmitted 
through  the  earth  should  for  any  reason  be  delayed  in 


366          VOLCANOES  AND  EARTHQUAKES 

reaching  a  distant  place,  the  great  sound  waves  should 
be  able  to  give  warning  of  the  coming  disturbances. 

Again,  as  we  have  already  seen,  the  earthquake  wave 
is  preceded  by  a  number  of  preliminary  tremors,  and 
is  followed  by  a  number  of  after  tremors  or  earthquake 
echoes.  Since,  therefore,  the  preliminary  waves  reach 
a  place  first,  it  would  seem  that  the  approach  of  an  earth- 
quake must  be  heralded  by  the  preliminary  tremors. 
These,  perhaps,  at  least  in  part,  enable  the  lower  animals 
to  detect  its  coming. 

Again,  in  almost  all  instances  there  are  a  number  of  pre- 
liminary shocks  that  precede  the  great  earthquake  shock. 
Some  of  these  preliminary  shocks  continue  at  intervals 
for  several  days  or  even  longer.  Sometimes,  indeed, 
these  subterranean  sounds  fail  to  be  followed  by  earth- 
quakes. Milne  thinks  that  these  sounds  are  caused  by 
the  preliminary  tremors  which  precede  the  principal 
shock  of  the  earthquake  and  that  they  reach  the  place 
first.  Here  again  then  it  is  evident  that,  were  we  able 
to  interpret  properly  these  sounds,  we  would  probably 
be  able  to  foretell  the  coming  quake  with  a  fair  degree 
of  certainty. 

There  would  appear  to  be  no  reasonable  doubt  that 
in  some  manner  which  we  have  not  yet  been  able  to 
discover,  but  probably  along  some  of  the  lines  indicated 
above,  animals  are  capable  of  recognizing  a  coming  earth- 
quake. Long  before  the  coming  of  the  catastrophe  they 
are  said  to  exhibit  extreme  terror,  and  in  many  cases 
appear  to  seek  the  companionship  of  man,  as  if  for  pro- 
tection. 

That  the  senses  of  smell  and  hearing  are  far  more  acute 
in  the  lower  animals  than  in  man  no  one  can  reason- 
ably doubt.  The  manner  in  which  a  trained  dog  can 
follow  a  scent,  for  a  long  time  after  the  animal  or  thing 


NATURE'S  WARNING  367 

producing  it  has  passed,  far  exceeds  the  power  of  scent 
possessed  by  man,  and  it  is  more  than  likely  that  this 
same  power  is  possessed  by  all  animals  who  live  upon 
or  prey  upon  other  animals.  It  is  probable  that  faintly 
odorous  vapors  or  gases  escape  from  the  crust  shortly 
before  the  great  shock  occurs,  and  that  these  faint  odors 
are  warnings  to  the  animals  of  the  approaching  calamity. 
The  sense  of  hearing  also  is  much  more  acute  in  the  lower 
animals. 

Daubeny  is  evidently  of  this  belief,  as  will  be  seen  from 
the  following: 

"These  gases  and  vapors  (alluding  to  emanations  given 
off  from  the  ground  during  earthquakes)  exert  an  in- 
fluence on  the  barometer,  which  does  appear  to  be  in- 
directly affected  by  the  earthquake.  Then,  similar 
properties  also  may  occasion  that  uneasiness  which 
animals  are  said  to  evince  before  any  such  event.  Thus, 
according  to  the  accounts  of  some  writers,  rats  and  mice 
leave  their  holes,  alligators  seek  the  dry  land,  quadrupeds 
snuff  the  ground,  and  manifest  such  signs  of  the  im- 
pending calamity  that  in  countries  where  earthquakes 
are  common,  the  inhabitants  take  the  alarm  in  conse- 
quence, and  escape  from  their  houses.  It  is  right,  how- 
ever, to  add,  that  more  recent  authorities  dispute  alto- 
gether the  correctness  of  these  statements. " 

Button  doubts  the  ability  of  animals  to  foretell  coming 
earthquake  shocks. 

But  that  the  lower  animals  do  exhibit  signs  of  fear 
at  the  approach  of  an  earthquake  has  been  repeatedly 
asserted  by  good  observers. 

Hamilton,  who  made  a  careful  examination  of  the 
neighboring  country  during  the  great  earthquake  at 
Calabria,  asserts  that  horses  and  oxen  during  the  shocks 
extended  their  legs  widely  in  order  to  avoid  being  thrown 


368         VOLCANOES  AND  EARTHQUAKES 

down,  "and  that  hogs,  oxen,  horses,  and  mules,  and  also 
geese,  appeared  to  be  painfully  aware  of  the  approach 
of  the  earthquake  of  Calabria;  and  the  neighing  of  a  horse, 
the  braying  of  an  ass,  or  the  cackling  of  a  goose,  even 
when  he  (Hamilton)  was  making  his  survey  (after  the  oc- 
currence of  the  great  earthquake  shock),  drove  the  people 
out  of  their  temporary  sheds  in  expectation  of  a  shock." 

It  is  asserted  that  birds  appear  to  be  especially  sensible 
to  a  coming  earthquake  shock.  That  geese  will  quit 
the  water  in  which  they  were  swimming  before  the  earth- 
quake and  will  not  return  to  it.  It  is  quite  possible  that 
these  birds  with  their  heads  immersed  in  the  water  can 
hear  the  distant  murmurings  long  before  they  become 
audible  in  the  air. 

Von  Hoff  makes  the  following  statement: 

"  It  has  been  remarked  that  at  such  times  (immediately 
before  the  coming  of  an  earthquake  shock),  domestic 
animals  showed  a  decided  uneasiness,  dogs  howled 
mournfully,  horses  neighed  in  an  unusual  manner,  and 
poultry  flew  restlessly  about.  These  latter  phenomena 
might  easily  be  produced  by  mephitic  vapours,  which 
often  ascend  to  the  surface  of  the  earth  before  the  break- 
ing out  of  an  earthquake." 

Mallet  states  that  there  is  abundant  evidence  that 
earthquake  shocks,  even  when  not  of  very  great  intensity, 
produce  nausea  in  both  men  and  women.  This  would 
seem  natural,  since,  as  everyone  knows,  until  one  is 
accustomed  to  sea-voyages,  merely  to  be  tossed  to  and 
fro  by  the  motion  of  the  waves  results  in  the  production 
of  sea-sickness. 

It  has  been  also  noticed  that  during  earthquakes  fish 
which  under  ordinary  circumstances  live  in  the  mud  at 
the  bottom  of  bodies  of  water  come  near  to  the  surface 
and  at  such  times  can  be  caught  in  great  numbers. 


NATURE'S   WARNING  369 

Mallet  cites  the  following  effects  produced  by  earth- 


"  Amongst  the  effects  supposed  to  be  produced  by  the 
earthquake  on  the  atmosphere  were  reckoned  tempes- 
tuous winds,  thunder-storms,  meteors,  coldness  of  the 
air,  severe  winters,  heavy  rains,  miasmata,  producing 
diseases  and  affecting  vegetation.  A  very  remarkable 
instance  of  the  latter  is  quoted,  namely,  that  in  Peru, 
after  the  earthquake  of  1687,  wheat  and  barley  would 
not  thrive  at  all,  though  formerly  the  country  was  re- 
markably favourable  for  them." 

Sir  Charles  Lyell  notes  the  following  phenomena  at- 
tending earthquakes: 

"Irregularities  in  the  seasons  preceding  or  following 
the  shocks;  sudden  gusts  of  wind,  interrupted  by  dead 
calms;  violent  rains  at  unusual  seasons,  or  in  countries 
where,  as  a  rule,  they  are  almost  unknown;  a  reddening 
of  the  sun's  disk,  and  haziness  in  the  air,  often  continued 
for  months;  an  evolution  of  electric  matter,  or  of  in- 
flammable gas  from  the  soil,  with  sulphurous  and  me- 
phitic  vapours;  noises  underground,  like  the  running 
of  carriages,  or  the  discharge  of  artillery,  or  distant 
thunder;  animals  uttering  cries  of  distress,  and  evincing 
extraordinary  alarm,  being  more  sensitive  than  men  to 
the  slightest  movement;  a  sensation  like  sea-sickness, 
and  a  dizziness  in  the  head,  experienced  by  men.  These, 
and  other  phenomena,  less  connected  with  our  present 
subject  as  geologists,  have  recurred  again  and  again  at 
distant  ages,  and  in  all  parts  of  the  globe." 

THE    END 


A  A      000277171    5 


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